It's the sauce I have to have.

Right now, my cupboard has three jars of it. If I get down to two, I have vague feelings of unease. Just one, I may start hyperventilating. If an open jar on the refrigerator door is all there is . . . don't ask. It could get ugly.

That's how strongly I feel about hoisin.

The thick molasses-colored sweet and spicy Asian sauce is, to my mind, one of the greatest cooking condiments ever invented and a pantry necessity. There is little this stuff can't improve. Okay, maybe brownies. But not much else.

And in terms of saving your fanny when you've had a brain lapse and can't think of a single thing to make for dinner -- trust me, hoisin is the greatest quick fix since pizza home delivery.

Hoisin (pronounced HOY-sihn) is a thick mixture of soybean paste, garlic, sugar, chilies and various spices.

How does it taste? Think Chinese spareribs. Think barbecue sauce but richer, more intense. Think mahogany-colored hoisin Cornish hens -- one of the most-requested Dinner Tonight recipes the Food section has ever published. Think Peking duck, says Chinese cooking authority Ken Hom, which in this country invariably is served with hoisin sauce mixed with a little sesame oil.

Jars of hoisin sauce can easily be found in the supermarket (usually near the soy sauce). Although it's widely used in Chinese cooking, the Chinese mainly consider hoisin a table condiment. Little glass containers of it show up in Chinese restaurants the way bottles of ketchup do in American places. In fact, at least one chef I know refers to it as "Chinese ketchup," it's that ubiquitous.

Fortunately, it's much more versatile than the red stuff.

I use it to lacquer a split chicken for Chinese barbecued chicken. I use it in a marinade for leg of lamb or flank steak (and the leftovers in a stir-fry with more hoisin the next day). I mix it with orange marmalade for a roast chicken glaze. I use it, cut with some soy sauce and chili paste, as "glue" to keep a sesame-seed coating on my salmon before baking (an idea I got from New Heights chef Matthew Lake). And on really bad days, I'll pan-fry some frozen Chinese dumplings, pass a bowl of hoisin-and-soy sauce for dipping and consider myself a culinary genius.

"Oh, my god, hoisin -- it's my no-brainer dinner," says New Englander Nina Simonds, author of "China Express" (Morrow, 1993). The busy mother of a 9-year-old, who's also working on a new cookbook and teaching cooking classes, says her favorite save-the-day dinner is to marinate a chicken with hoisin, chopped garlic, soy and American ketchup. "That's it. It makes your house smell good. It's delicious."

Hoisin, Simonds says, "tastes familiar to people, maybe because it touches on the same flavors as barbecue sauce." And, like barbecue sauce, it goes best with roasted meats "or anything that tastes sort of fatty," she notes, "like pork, duck and salmon."

Or tofu. Simonds loves to make a cold noodle salad using hoisin and chili paste in a spicy stir-fry sauce for water chestnuts and cubed tofu, then tossing the warm ingredients with cool crunchy shredded vegetables and soft noodles. "It's just extraordinarily versatile," she says of the sauce.

For New Heights chef Matthew Lake, the guy who calls it Chinese ketchup, hoisin can work wonders even in very small quantities. It's a great "bridge ingredient," helping to tie other flavors together, he says. He uses just a touch of hoisin to balance the flavors in his coconut curry soup, and adds a hint of sweetness with it to a soy reduction sauce for seared tuna.

He also knows that customers like hoisin's flavor in a big way: His Woodley Park restaurant's new winter menu features salmon with a hoisin glaze.

Robert Hile, chef at the new P.F. Chang's China Bistro in Tysons Galleria, says hoisin is a mainstay of the barbecue sauce they use on the restaurant's popular ribs and pork tenderloin, as well as in the mu shu chicken. He prefers the Koon Chun brand, which is thick -- almost jammy -- and a little sweeter than most.

Although he loves the combination of chicken, carrots and hoisin -- "they were made for each other" -- Hile also likes the sauce for Hunan-style steamed fish. He slathers a whole fish with hoisin, chili paste, rice-wine vinegar and soy sauce and lets it steam. "It perfumes up really nice when it gets hot," he says.

What makes hoisin so appealing in so many different dishes, says Philadelphia cookbook author and hoisin fan Andrew Schloss, is its perfect balance of sweet, sour and salt. "Those are the three positive flavors on your tongue," says the former cooking school instructor. "You can taste them all at once in hoisin, and they zap back and forth in your mouth. It tastes exciting."

Schloss, whose newest books are "One-Pot Cookies" and "One-Pot Chocolate Desserts" (Broadway, $12.95 each), agrees that hoisin complements roasted meats, but he's willing to take it even further. He thinks the sauce's natural sweetness may even work in a dessert.

"It would go best with chocolate -- maybe just under the flavor," he muses. "Want me to see if I could come up with a recipe?"

Uh, no. There's a limit to my love. Chinese Barbecued Chicken (4 servings) A perennial favorite, this is also known as Nina Simonds's no-brainer dinner. The author of "China Express" (Morrow, 1993) says that not only will this dish fill your house with a delicious aroma, but the all-purpose sauce is great on pork spareribs as well. She suggests serving it with broccoli in oyster sauce and rice.

1 split fryer or broiler chicken (about 3 1/2 pounds)

1/2 cup hoisin sauce

3 tablespoons soy sauce

3 tablespoons rice wine or sake

2 tablespoons sugar

2 tablespoons ketchup

2 tablespoons minced garlic

Rinse the chicken and drain thoroughly. Place the chicken halves in a bowl. Combine the hoisin and soy sauces with the rice wine, sugar, ketchup and garlic and pour over the chicken. Toss lightly to coat, and spread the mixture all over the outside and inside of the chicken. Cover with plastic wrap and refrigerate for at least 1 hour, or overnight if possible.

Preheat the oven to 375.

Arrange chicken halves skin-side down on a baking sheet lined with aluminum foil. Bake for 30 minutes, turn over and bake for another 30 minutes until crisp and brown. Let the chicken cool slightly before cutting the halves into desired serving pieces. Arrange on a platter and serve.

Per serving: 446 calories, 51 gm protein, 13 gm carbohydrates, 20 gm fat, 148 mg cholesterol, 6 gm saturated fat, 879 mg sodium Hoisin Hens (4 servings)

This recipe from local cook Polly Clingerman ran in the Food section in 1993 and we still get requests for it. The hens are cooked in a thick, dark, hoisin-flavored sauce and come out looking and smelling as good as they taste.

2 tablespoons vegetable oil

2 Cornish game hens, split into 4 halves

1 cup diced onion

2 teaspoons minced garlic

1 1/2 teaspoons minced fresh ginger root

1/4 cup soy sauce

1/4 cup hoisin sauce

1/4 cup dry sherry

1/4 teaspoon hot pepper flakes

1/2 cup chicken stock

Place a wok or heavy pot that will just hold the hen halves over high heat. Add the oil. When it is hot, add the hens, breast-side down. Reduce the heat to medium, cover and cook for 6 minutes, turning halfway through. Add the remaining ingredients. Cover and simmer over medium-low heat for 40 minutes, turning halfway through.

Remove the hens. If the sauce isn't thick and syrupy, continue to cook it, uncovered, for a few more minutes.

Serve the hens topped with the sauce on a bed of thin pasta that you have tossed with sesame oil (use 1 tablespoon oil per 12 ounces of pasta).

Per serving: 391 calories, 30 gm protein, 15 gm carbohydrates, 22 gm fat, 52 mg cholesterol, 2 gm saturated fat, 1477 mg sodium Mushrooms and Tofu in Hoisin Sauce (4 to 6 servings)

Dark, glossy hoisin sauce jazzes up tofu and makes this vegetarian dish a winner. Serve it over noodles with a simple steamed vegetable, and dinner's a cinch. From "Vegetarian Cooking for Everyone" by Deborah Madison (Broadway, 1997).

8 to 12 dried Chinese black or shiitake mushrooms

20-ounce block Chinese-style firm tofu, drained, or 2 10-ounce boxes silken firm tofu

2 tablespoons peanut oil

2 teaspoons chopped garlic

3/4 pound fresh white or shiitake mushrooms, stems removed from the shiitakes, caps quartered

Salt to taste

3 tablespoons rice-wine vinegar

Mushroom-soaking water plus vegetable stock to make 2 cups

2 teaspoons dark (toasted) sesame oil

1 tablespoon soy sauce

3 tablespoons hoisin sauce

1/2 cup chopped tomato, fresh or canned

2 teaspoons cornstarch dissolved in 2 tablespoons water

2 scallions, including the greens, sliced diagonally (optional garnish)

Put the dried mushrooms in a bowl with warm water to cover and let soak for 20 minutes or until soft. Reserving the soaking water, remove the stems from the mushrooms and cut the caps into quarters.

Cut the drained tofu into 1/2-inch cubes.

Heat a wok, add the oil and swirl it around the sides. When it's hot, add the garlic. Stir-fry for 30 seconds. Add the fresh and dried mushrooms and 1/2 teaspoon salt and stir-fry for 2 minutes. Add the vinegar, the 2 cups mushroom water plus stock, sesame oil, soy sauce, hoisin sauce and tomato. Stir everything together, then add the tofu. Lower the heat and simmer for 4 minutes. Add the dissolved cornstarch and cook until the sauce is thickened, another minute or so.

Served garnished with the scallions, if desired.

Per serving: 294 calories, 16 gm protein, 29 gm carbohydrates, 14 gm fat, 0 mg cholesterol, 2 gm saturated fat, 668 mg sodium Using Hoisin With a Light Hand

Noted Chinese cooking authority Ken Hom, author of several cookbooks, including the recent "Easy Family Recipes From a Chinese-American Childhood" (Knopf, 1997), calls hoisin the all-time great Asian barbecue sauce. His favorite use is on ribs, but he also calls the sauce a godsend for boring chicken breasts.

Unfortunately, he quickly adds, cocky young American chefs often over-use hoisin, and home cooks could use a little coaching as well. Here are his tips:

* If you're going to use hoisin as a glaze for a roast chicken or those bland breasts, be sure to salt and pepper the chicken before slathering on the hoisin. The little bit of saltiness and the bite of pepper really help balance the hoisin's sweet flavor.

* To use it as a dipping sauce, dilute it with some sesame oil and a little yellow bean sauce for saltiness. Hom recommends 1 tablespoon of yellow bean sauce to 3 tablespoons hoisin.

* Use it in stew, but be judicious. Add 2 to 3 tablespoons for a subtle, sweet richness.

* For fabulous barbecued ribs with hoisin, Hom does it this way: Salt and pepper the ribs and cook them for 1 hour in a 200-degree oven so that most of the fat drips away. Then mix together hoisin and chili bean sauce (for 1 cup hoisin sauce, use about 2 tablespoons chili bean sauce, or more if you like things really spicy). Brush the hoisin mixture on the ribs and grill them, turning once, until they're nice and dark and done the way you like them. Serve with lots of napkins.

* The same hoisin barbecue sauce for ribs works equally well on quail.