DOING SUSHI is California's newest eating shtick. In New York they merely eat it . . . in any one of 40 different Japanese restaurants that have sushi bars. Here in Washington we have three choices for the popular Japanese combination of vinegared rice and raw fish. And that's a third more than we had six weeks ago.

If Washington isn't "doing sushi" yet, it isn't surprising. According to Kojiro Inoue, the chef-owner of Samuri-Sushiko in upper Georgetown, only 600 Japanese live in the city, many of them connected with the embassy. Still, most of his clients, he says, are Caucasians. That is not the case at the newest sushi bar-restaurant in Bethesda, Takane, where most of the customers one night last week were Japanese. The chefs from both rstaurants come from Sakura Palace in Silver Spring.

Describing sushi as rice and raw fish is not really accurate. Sometimes the fish isn't raw, for one thing. And other things besides fish are used. There are three kinds of sushi: each is a different shape; all are beautifully arranged. The most popular is nigiri-sushi, vinegared rice ovals or balls topped with seafood. Then there are the rolls called norimake-sushi in which the rice is spread with ingredients like mushrooms, cooked egg and spinach and then rolled in seaweed on a little bamboo mat. The third variety is chirashi-sushi. The rice is heaped in a bowl and then artistically decorated with bits of egg, fish, tofu (bean curd) and ginger. The sushi are almost always served with pickled ginger and seasoned with a powerful green horseradish called wasabi.

Sushi-lovers are made, not born. Learning to love raw fish, in a culture which prides itself on overcooking its food, takes effort. And I must confess, the first time I had it, in Hawaii, I was not enamored. But looking back, my lack of enthusiasm may have had more to do with the fact that the meal took five hours, all of them spent sitting on a pillow without a back, eating Japanese-style.

Even Inoue's American-born children prefer hamburgers, and as a matter of fact, eat very lttle sushi. Maybe when they grow up they will mend their ways and discover what they are missing.

Within each type of sushi there are unlimited varieties. That helps to explain why Californians "do sushi." They spend a lot time making choices. Sushi can be ordered by the piece. Since each one is made to order, it takes a considerable amount of time to consume a meal of sushi, even though you are supposed to put the entire piece in your mouth at one time. This may not be the way you are used to eating, but sushi is served with chopsticks, not knives and forks, and it gets sort of sloppy trying to tear the piece of fish in half with your teeth.

One of the delights of eating sushi is watching the sushi chef work. The speed with which his knife turns whole fish into fillets and then into paper-thin slices makes one a believer in the old adage that the hand is quicker than the eye. The chef works behind a counter where the various ingredients are displayed in a refrigerated glass case.

There are thousands of sushi bars in Japan, and within the last few years hundreds of fast-food sushi bars have opened. The quality of their product isn't like that of the traditional sushi restaurant, Inoue said, where a meal can cost $50 to $75 a person. Sushi is also eaten as a light lunch or a quick snack and frequently finds its way into picnic baskets.

It takes a minimum of five years to become a good sushi chef, according to Inoue, who has been at it for 19 years, first in Japan, then at Sakura Palace in Silver Spring and now in his own restaurant. "You have to learn the cutting. You have to learn the shapes, about the different seasons. Every day fish and vegetables change." But above all, Inoue says, "you have to be quick".

In order to be a first-class sushi chef in Japan you also have to know how to prepare sashimi, slices of raw fish artistically arranged and the potentially lethal blowfish , a Japanese delicacy. If the liver of the fish is not properly cleaned, the aficionado can find himself dead on the floor. Despite the number of deaths each year from improperly cleaned blowfish, people can't get enough of them. Inoue says he can "clean a blowfish with his eyes closed."

Seasonal cooking is one of the cornerstones of Japanese cuisine. According to Elizabeth Lambert Ortiz and Mitsuko Endo in "The Complete Book of Japanese Cooking," in Japan there is" an appreciatin of foods appearing at their appointed times . . . There is also an appreciation of how foods are best eaten at certain times of the year."

Meticulous attention to detail also characterizes the cooking. More than almost any other cuisine, Japanese food is a feast for the eyes as well as the stomach. Because of the care with which it is cut, it looks exquisite. aIt has a very spare quality which has been adapted by the followers of nouvelle cuisine.

Japanese cooking is very light and straightforward. Like Chinese cooking it contains little fat, so it fits right in with new American concerns about health. Perhaps that is one f the reasons so many people are "doing sushi."

Perhaps, on the other hand, it's because it tastes so good. Have it with hot tea, cold beer or warm sake.

If you would like to try some of the simpler sushi varieties at home, there are several markets that carry all of the of the ingredients: The Mikado, House of Hanna and Fumi.Many other Oriental markets carry some, but not all of the ingredients. Don't let the length of the recipes scare you off. Almost everything can be prepared in advance, some things as much as two or three days before.

These recipes ar from "The Complete Book of Japanese Cooking." SHUSHI (Rice with Vinegar Dressing) 2 cups rice 3-inch square kombu (kelp) (optional) 2 1/4 cups water 1/4 cup rice vinegar 1 tablespoon sugar 2teaspoons salt 1/2 teaspoon msg (optional)

Thoroughly wash the rice in several changes of water until the water runs clear, and drain in a sieve for at least 1 hour. Put into a heavy saucepan with a tightly fitting lid. Clean the seaweed with a damp cloth and cut with kitchen shears into a 1/2-inch fringe. Bury the seaweed in the rice. Add the water, cover and bring to a boil over high heat, removing the seaweed just before the water boils.Otherwise it will flavor the rice too strongly. Reduce the heat to moderate and cook for 5 or 6 minutes, then reduce the heat to very low and cook for 15 minutes. Raise the heat to high for 10 seconds, then let the rice stand off the heat for 10 minutes.

In a small saucepan combine the rice vinegar, sugar, salt and msg. Heat through, stirring to mix.Turn the rice out into a large, shallow dish, preferably wooden. Pour the vinegar mixture little by little over the rice, mixing it with a wooden spatula or a fork, and fanning it vigorously to make it glisten. It is agood idea to have a helper do the fanning, though it can be managed alone. The fanning cools the rice quickly and this is what makes it glisten.

Cover the rice with a cloth until ready to use. It can be left standing at room temperature for several hours before using if necessary. NORIMAKIZUSHI (Vinegar Rice Rolled in Seaweed) (4 to 6 servings) 2 cups rice 4 shiltake (Japanese dried mushrooms) Sugar 2 tablespoons plus 1 teaspoon soy sauce Ten 9-inch pieces kanpyo (dried gourd strips) Salt 2/3 cup dashi (soup stock) 3 tablespoons mirin 2 tablespoons usukuchi shoyu (light soy sauce) 1/4 pound filet of sole 2 eggs, stirred Vegetable oil 1 tablespoon sake 1 1/2 cups tightly packed spinach 4 sheets nori (dried layer seaweed) Pickled red ginger

Cook the rice and season it with the vinegar mixture according to the recipe for Sushi.

Rinse the mushrooms and soak in water to cover for 30 minutes with a pinch of sugar. Squeeze out lightly and cut away the hard stems. Put into a saucepan with the water in which they soaked and cook over moderate heat, uncovered, until the liquid is reduced by 1/4, about 4 minutes. Add 1 tablespoon sugar and simmer for 5 minutes longer, turning the mushrooms from time to time. Add the 2 tablespoons of soy sauce, reduce the heat to low and cook, turning once or twice, for 3 minutes longer or until the liquid has evaporated. Cool, squeeze cut any moisture, and cut into 1/3-inch diagonal slices. Put on a large plate.

Sprinkle the gourd strips with salt and wash, rubbing lightly. Soak in warm water for about 2 minutes, place in a small saucepan with water to cover, bring it to a boil and simmer for about 2 minutes. Drain. Return the strips to the saucepan with the soup stock, bring to a boil over high heat, then add 1 tablespoon each of sugar and mirin and cover with a smaller saucepan lid that will fit on top of the contents of the pan. Or use a plate. Cook for 10 minutes over low heat, then add the light soy sauce and simmer for 5 minutes longer. When cool enough to handle squeeze out and put on the plate with the mushrooms.

Pound half the fish to a paste with 1 tablespoon each of sugar, mirin and water and 1/4 teaspoon salt, then add the eggs, little by little, mixing well. Lightly oil the sides and bottom of an 8-inch covered skillet as well as the inside of the lid. Heat the skillet, pour in the egg mixture, reduce the heat to very low and cook for about 3 minutes. Using the lid, turn the omelette, add a little more oil to the pan and lightly brown the other side. Lift and lightly brown the other side. Lift out, cut into 1/3-inch strips and add to the plate beside the mushrooms.

Rinse out and dry the skillet and half fill with water.Bring to boil, add the other half of the fish and simmer until the fish loses it boil, add the other half of the fish and simmer until the fish loses its translucent look, about 2 minutes. Lift out and drain on a piece of cheesecloth, squeezing out the moisture and breaking up the fish. Pour the water out of the skillet, add the fish, the sake, 1 teaspoon of sugar, the remaining tablespoon of mirin and alst to taste. Cook, stirring over low heat until the mixture is dry and grainy. This is soboro which can also be made with shrimp or bought ready made in jars in Japanese markets. cPut with the other ingredients on the plate.

Wash the spinach and drop it into a large saucepan of boiling salted water, bring back to a boil and cook for 1 minute. Drain and squeeze dry. A bamboo mat is useful for this. Form into a roll and sprinkle with the teaspoon of soy sauce; let stand for a few minutes, then squeeze out again. Add to the plate. Divide each of the ingredients into 4 portions.

Lay a bamboo mat on a wooden chopping board and place a sheet of seaweed on it. Wet the hands with rice vinegar and pat 1/4 of the rice evenly over the seaweed leaving a 1/2-inch border along the bottom. Starting from the top, about 1 1/2 inches from the edge, arrange 1/4 of the spinach on top of the rice in a horizontal row. Next to the spinach make a row of omelette strips, then gourd strips, then soboro, then mushrooms. Roll up the seaweed, using the bamboo mat to help pressing lightly but firmly to make a neat cylinder. Let it rest a minute or two in the mat, then unroll and set aside. Tap the ends of the roll on the chopping board to firm them up. Repeat with the remaining ingredients to make 4 rolls. Using a sharp knife wiped with a cloth wrung out in cold vinegared water, cut the rolls into 3/4-inch slices, about 9 to a roll. Arrange on individual platters, garnish with thin slices of ginger and eat with chopsticks or by hand. NIGIRI-ZUSHI (Handmade Sushi) (4 servings as main course, 8 to 16 as appetizer) 2 cups rice 3/4 pound cleaned fish or shellfish: tuna, striped bass, sea bass, porgy, red snapper, squid, cuttlefish, octopus, clams, sea urchins, salmon, caviar, abalone, scallops 8 medium-sized raw shrimp, about 1/4 pound Salt 1 teaspoon rice vinegar 1tablespoon wasabi (green horseradish powder) Soy sauce

Cook the rice and season it with vinegar mixture according to the recipe for Shushi.

Cut the fish into 1/4-inch-thick diagonal slices about 1-by-2-inches. There should be about 24 slices. Remove the intestinal vein from the shrimp with a toothpick, but do not peel. Using small bamboo skewers, or toothpicks, skewer the shrimp full length on the underside to keep them from curling when they are cooked. Drop the shrimp into rapidly boiling salted water with the vinegar and boil over high heat for 1 1/2 minutes. Drain, remove the toothpicks, peel the shrimp and cut along the underside three-quarters through, taking care not to cut too deeply. Gently open and flatten out the shrimp. In a small bowl mix the wasabi powder to a stiff paste with a little cold water and set aside.

Wet hands in wate to which a little rice vinegar hs been added and form about 2 tablespoons of the sushi rice into an oblong patty about 1-by-2-inches. aSpread a dab of horseradish paste down the center of a piece of fish and place the fish, horseradish side down, on top of the rice. Continue until all the fish is used. Place the shrimp on top of patties of rice in the same way, but without any horseradish. Arrange the shushi on a large platter and place in the center of the talbe with some wasabi paste and a tiny bowl of soy sauce at each place setting, or arrange on individual platters. To eat, dip one end of the shushi in the soy sauce, using either chopsticks or fingers.