Out in the middle of rural Buckingham County, Virginia--population 11,751--there's a mushrooming business that its president hopes will stun competitors and consumers alike and revolutionize the industry in the United States. His company has started growing mushrooms, big mushrooms, thousands of pounds of mushrooms each year, mushrooms that he hopes will change America's concept of what mushrooms are all about.

These are mushrooms that Japanese call shiitake, Chinese call dong and Koreans call huang skin, and they are very much unlike what Americans know familiarly as button mushrooms. Their botanical name is Lentinus edodes, and for the past 10 to 15 years these mushrooms, native to the Far East, have been cultivated, dried and exported under the name Black Forest mushrooms to Oriental markets in the United States and around the world.

They are also commonly known as oak tree mushrooms, but in Buckingham County these magnificent mushrooms are called Golden Oaks--golden for their chestnut brown color, oak for the type of logs on which they grow. Giving these mushrooms a new American name is not just a marketing ploy, according to mushroom entrepreneur Seung-Il Shin. He believes that with the Virginia climate, the plentiful oaks, and high-tech mycological know-how imported from Korea, his Elix Corp. will soon develop a new strain of shiitake mushroom--bigger, more tasty, denser, and in the long run less expensive than any shiitake seen in this country.

According to devotees, shiitakes have it all over button mushrooms. They're bigger, firmer, more fleshy, almost meat-like in texture, have a more distinct, almost-aromatic flavor, and yet they respond to ingredients with which they are cooked. They're said to have more nutrients, particularly higher protein, than the common Agaricus, or button, mushroom.

But growing requirements for shiitake mushrooms might limit the industry. Shiitakes grow on logs rather than in soil, outdoors rather than in damp, moist, darkened beds. Their growing habitat of oak forests and cool humidity is not as easily controlled as the normal indoor habitat of commercial button mushrooms.

Indeed, button mushroom culture has become big business in the United States over the last 20 years. In 1982-83, almost half a million pounds of button mushrooms, worth $431 million wholesale, were grown in the United States. More than half of the crop came from Pennsylvania, although three dozen other states shared in the crop. Shiitakes are grown in the United States only on a few farms on the East and West coasts and production is less than 10 percent of the button mushroom crop.

The story of the Elix Corp. begins eight years ago--or more like 40 if traced back to its true origin. In the little town of Wonju, Korea, just outside Seoul, two boys sat in a schoolroom together. In time, Shin went on to college in the United States, studying biochemistry at Brandeis and eventually becoming a research geneticist at New York's Albert Einstein College of Medicine. Eung-Sik Weon remained in the countryside near Seoul, becoming an expert mushroom farmer.

"He was one of the first to export mushrooms on any large scale," said Shin, describing the entreprenurial savvy of his friend. As Weon watched orders from overseas buyers steadily increase, he saw the potential for his mushroom business grow, ironically in inverse proportion to the dwindling number of trees available for mushroom culture in his homeland of Korea. Weon contacted his old schoolmate Shin, who by this time knew the United States well.

"At first I said I wasn't interested, because I knew nothing about mushrooms, and very little about business," said Shin of his response to Weon's request to help him relocate his mushroom business in the United States. "But we drove around, about 2,000 miles, up and down the eastern seaboard from New York to North Carolina, scouting around for the right place to grow mushrooms. Because of the similarities of climate and terrain between the Shenandoah Valley and Korea, I suspected that this area would have conditions that would favor growth. It turned out that this part of Virginia was optimal. The factors we were looking for were fresh water, good quality oak and availability of labor."

Buckingham County is not wealthy. Pulpwood and timber wood are its major industries. Families crowd into trailers set up on concrete blocks in little patches of yard carved out of the forest, with lush green vegetable gardens planted alongside. Many people in Buckingham County are willing workers but are unemployed these days.

Shin and Weon settled into a 55-acre tract 28 miles south of Charlottesville, in an area thickly forested with oak, tulip poplar and Virginia pine. Several springs trickled through the property.

"When I first come here, all trees, all trees. No road," said Weon as he weaved his way along slate-strewn roadbeds, through the maze of oak logs now cut to length, stacked and implanted with the spores of Golden Oak mushrooms. Weon is a rugged little man, long waisted, wearing blue jeans, sneakers and a baseball cap.

There are 17 kinds of oak trees in the area, according to Weon, although he uses only four--chestnut, red, black and white. He is testing other common woods that can be cut on the property--hickory, cherry, tulip poplar and sweetgum. But oak, the traditional growing medium for these mushrooms, still seems to work best.

Rough roads, imprinted with the deep tracks of tractor tires, wend through seemingly endless stacks of oak logs. Small cardboard signs tacked onto an occasional tree, with Korean symbols scrawled in red magic marker, are the only guide to what's happening, and Weon admits he keeps a lot in his head. In all, 250,000 logs are stacked over 28 acres, each log about five feet long, diameters ranging from three inches to a foot. Each log has been hand-drilled with several dozen half-inch deep holes, into which the white, moldy-looking mushroom spawn was placed in the spring. White plastic foam plugs keep the spawn in place, encouraging its growth outward through the log, between bark and wood. Virginia pine trees offer natural shade throughout most of what Weon calls the staging area. Where the pines don't grow, huge black mesh tarpaulins, manufactured for the tobacco industry, stretch out over still more stacks of logs.

Once a log is impregnated with mushroom spawn, it begins a three-to-eight- year life of production. The first sign that mushroom growth is proceeding comes at the cut end of the log, where spots or a ring of white show that the spawn has spread from the interior of the log. Weon moves from stack to stack, checking for white coloration, tending to any that are coloring wrong.

If a moldy green color appears instead, the result of too much water, he says they are "sick." He gestures as if sick to his stomach and says, "You go to hospital." His crew knows that when he says "hospital," he means a sunny area near the shiny new Quonset hut used as a packing shed. A short stay in the sun should cure an ailing log and after a few days of treatment, Weon raps the log with his knuckles. He listens to determine if it is now less waterlogged and notes, "You happy now. Go home," and workers replace the log on the stack in the shade where it began.

When the time is right--and only Weon seems to sense that, or hear it (so he claims) from the logs themselves--the logs are lifted and restacked, either end-up, tepee fashion, resting against a living tree, or side-to-side, like a giant three-dimensional tick-tack-toe game. The first blush of mushrooms is coaxed out with a carefully timed sprinkler system, but from then on Weon subjects the logs to more drastic treatment. When they next tell Weon they are ready to sprout, workers hoist them with specially rigged farm machinery and dunk them into one of two spring-fed ponds for about 12 hours before they are taken out to shady spots.

Up from under the logs sprout forest-brown mushrooms, big as a strong man's hand. Their caps are velvety brown with a white, ring-like, cotton tuft circling round the center. Some seasons they grow more tortoise-style, with nooks and crannies cracking open on top of the cap like a crusty baked meringue. The gills are large, well-defined, and silky white. The stalks are firm and fuzzy, too fibrous to eat. Some mushrooms grow singly, reaching up vigorously from the log. Others cluster. A tender twist on the stalk pulls the ripe mushroom from the log on which it grew.

"We broke a record this year," said Shin, who as president of the Elix Corp. manages the business from his home in New Rochelle, N.Y. "We produced the first crop three months after we planted"-- a record speed, here or in the Orient, he reported. "Climate conditions are right, the logs have been very good, and also we have introduced a very efficient management system, with irrigation and improved technology."

Each log has the capacity to sprout about a half pound of mushrooms four times a year, becoming dormant only three months in the winter. Having impregnated 250,000 logs, Elix Corp. expects about half a million pounds of mushrooms to ripen next year. And Shin and Weon believe it's just beginning.

In the Washington area, the mushrooms will be distributed to stores and restaurants by Bernard Furin, head of Braun's Fine Catering in Chillum, Md. "We've had new ways of fixing things, but not new items," says Furin. "And especially not a fresh mushroom the size of this one."

"They are beautiful, beautiful," said Boris Paskvan, who works with Furin at Braun's. Originally from Yugoslavia, where wild and flavorful mushrooms regularly spike the cuisine, Paskvan brought word of these stupendous mushrooms back to Braun's, after cooking and tasting them at a dinner he prepared at Sen. Mark Hatfield's home in.

"One thing about this mushroom that is so good--it is a meal in itself," said Paskvan. "You can cook it like a cordon bleu, with a salad on the side, and it's a meal in itself. It's really unlimited to work with."

"When you put it in your mouth, you know you have something," said Furin. "It's not a shriveled little oozy thing." They carry a distinct, earthy flavor all their own, but they also tend to absorb other flavors around them, he said. Furin serves them saute'ed and cold next to pineapple, and they take on the flavor of pineapple. Braun's also prepares a Coquilles St. Jacques with scallops, cream sauce and mushrooms, and the mushrooms are hard to tell from the scallops. Paskvan grills whole, fresh mushroom caps right on top of an electric stove burner, so that the circular pattern of the burner singes in. The distinctive, almost meaty flavor of the grilled mushroom comes through strongest when prepared the simplest way.

So far, the only real drawback to these mushrooms is their price. They will vary in the near future between $10 and $20 per pound, depending on the season, while button mushrooms are usually $2 at most. The lowest prices for shiitakes should be during the peak harvest, from September through November. But Shin foresees a time when Golden Oak mushrooms will be produced and sold in such great numbers that their price will drop to suit everybody's budget. He imagines that they will take their place alongside the white button mushrooms we already use, becoming a part of America's everyday cuisine. SALT-BROILED SHIITAKE MUSHROOMS (4 to 8 servings) 8 shiitake mushrooms Salt

Remove mushroom stems. Clean top and bottom of mushroom cap with damp cloth or paper towel. Place in broiler pan, gill side down. Sprinkle with salt. Broil 1 minute. Turn gill side up, sprinkle with salt, and broil another minute. Serve immediately. SAUTE'ED SHIITAKE MUSHOMS (4 servings) 4 tablespoons butter 4 tablespoons olive oil 3 cloves minced garlic 8 to 12 Shiitake mushrooms, caps only, wiped clean and sliced to 1/2-inch thickness 1/4 cup minced fresh parsley Salt and pepper to taste

Melt butter in frying pan; add oil and bring to sizzle. Toss garlic in pan until it begins to become golden, then toss mushroom slices in briskly. Cook for less than 1 minute over medium high heat. Add fresh parsley, salt and pepper. Serve immediately. STUFFED SHIITAKE MUSHROOMS (4 servings) 8 Shiitake mushrooms 1/2 cup olive oil 1/3 cup bread crumbs 2/3 cup grated parmesan cheese 1 tablespoon minced fresh basil 1 tablespoon minced garlic 1 teaspoon capers 2 tablespoons water

Remove stems from mushrooms and wipe caps clean with damp cloth or paper towel. Spread shallow baking pan with 2 tablespoons olive oil. Place mushrooms cap side down in pan. Blend remaining ingredients together and spoon onto each mushroom cap. Drizzle remainder of olive oil over mushrooms evenly. Spoon water in between mushrooms to add extra moisture. Cover baking pan and bake in 400-degree oven about 12 minutes. Serve either as a light entree or as a side vegetable. SHIITAKE CHICKEN (4 servings) 5 to 6 pounds chicken, cut into pieces 1/4 cup lime juice 2 tablespoons minced ginger root 2 tablespoons minced garlic 1 teaspoon soy sauce 1 teaspoon salt 1 teaspoon dry mustard 3/4 cup dry white wine, approximately 1 onion 1 cup sour cream 3/4 pound shiitake mushrooms (8 to 12 mushrooms)

Rinse chicken and cut into serving pieces if necessary. Combine lime juice, ginger, garlic, soy sauce, salt and dry mustard in a measuring cup; add enough dry white wine for ingredients to measure one cup. Stir to mix, then pour over chicken parts in large bowl. Marinate for at least 8 hours, occasionally spooning liquid over chicken and turning pieces.

Place chicken and marinade in shallow baking dish and bake, covered, at 350 degrees for one hour. Remove from oven, reset temperature at 400 degrees. Pour juice off chicken and combine it with sour cream. Slice mushroom caps and onions thinly and arrange them over chicken in baking pan. Pour sour cream gravy over all, bake uncovered at 400 degrees for 15 more minutes. SHIITAKES SAUTE'ED WITH BACON AND ONION (4 servings) 1 diced onion 8 slices bacon, diced 2 tablespoons butter 12 shiitake mushrooms, caps only, cleaned and sliced thinly 1 tablespoon minced parsley Salt and pepper to taste

Saute' onion and bacon together until bacon begins to turn golden brown. Melt butter in the pan, then immediately add mushrooms. Toss quickly, cover and turn heat to low for about 5 to 8 minutes. Add parsley, salt and pepper. Serve immediately. Serve over toast with an omelette for brunch or over pasta for dinner. ANCHOVY-OLIVE SHIITAKE CORDON BLEU (6 servings) 12 large mushrooms, caps only 1 3/4-ounce tube anchovy paste 5-ounce can pitted black olives, thinly sliced 4 tablespoons butter, softened 1 cup flour 2 eggs 1/2 cup water 1 1/2 cups bread crumbs Butter or olive oil or combination, enough for frying

Clean mushrooms with damp cloth or paper towel. Spread gills lightly with butter. Pair up mushroom caps according to size, then onto one of each pair spread about an inch-long squirt of anchovy paste. Sprinkle olives on top, then close two mushrooms together, gills in, to sandwich the anchovy paste and olives.

Bread each pair of mushrooms by dipping into flour, then egg whisked together with water, then bread crumbs. Hands or tongs will keep the mushrooms sandwiched together. Fry both sides briefly in butter or oil. With salad, makes a splendid dinner.