The amber-colored sesame oil of China and Japan, used primarily as a flavoring, is a prime contender for the world's most seductively flavored oil. It not only lends its own nutty fragrance to a dish but also enlivens the other flavors.

This is why the northern Chinese, the foremost consumers of sesame oil, sprinkle a few drops over almost everything they cook just as the heat is turned off. Up to a tablespoon is dribbled over hearty soups such as hot and sour just before serving.

Sesame oil is used like salad oil in dressing room-temperature Chinese dishes and is mixed with vinegar, soy sauce and sometimes chili paste to make a standard dip for dumplings. Because of its expense, sesame oil isn't a standard table condiment in Chinese restaurants, but if you order dumplings and are a known customer the restaurant may provide you with a bottle; or you can request it.

Sesame oil comes by its enchanting aroma from sesame seeds that are roasted before their oil is extracted. Light-colored oil pressed from raw sesame seeds, though good for cooking, is not an acceptable substitute for this fragrant oil; in fact there is none. By the same token the oil from roasted seeds makes a poor cooking oil as it burns easily and loses much of its fragrance when heated. This is why it's used as a finishing touch (it's also rather expensive to cook with).

One notable exception is tempura oil, which is blended by Japanese chefs according to taste and may contain as much as half sesame oil. The effect of deep-frying batter-coated vegetables and seafood in part sesame oil -- usually blended with soy bean and rapeseed oil -- is very subtle though absolutely necessary according to Japanese gourmets. Sichuan chefs make a seasoned oil by blackening dried chili peppers and Sichuan peppercorns in sesame oil, then straining it to use for cooking or dribbling over dishes. The slightly burned flavor in this case is desirable.

Sesame oil, used medicinally both externally and internally, is sort of a cod-liver oil of the East. It makes a luxurious massage medium when combined with fresh ginger juice to relive aches and pains. It is thought to facilitate the labor of childbirth, and black sesame oil sometimes seen in Chinese markets is perhaps more valued as a postpartum restorative than a flavoring ingredient.

There is no reason why sesame oil can't work its magic with American dishes. A teaspoon beaten with eggs to be scrambled yields a more flavorful result. It's excellent for basting roasting chickens and turkeys. A few drops can be added to salad dressings, and it goes especially well with mustard. A vinaigrette made with sesame oil is delicious with parboiled asparagus and other vegetables.

Plastic squeeze bottles are becoming the packaging of choice for sesame oil, and this is unfortunate, as the oil seems to turn rancid more quickly in this kind of container. Look for glass bottles, or cans if you buy in quantity. The most reliable brand is Kadoya of Japan, which sells for about $2.60 for 12 ounces or about $8.60 for a beautiful lavender tin of just under 2 quarts. Slightly more expensive but also excellent is the Taiwanese brand Kinlan, with its red-labeled bottles. SESAME OIL VINAIGRETTE WITH ASPARAGUS (4 servings)

2 pounds asparagus or 1 1/2 pounds other vegetables or greens

1 teaspoon finely minced garlic

1/2 teaspoon salt

1/2 teaspoon freshly ground white pepper

2 teaspoons imported mustard such as dijon

1 1/2 tablespoons fresh lemon juice

4 tablespoons sesame oil

If asparagus is used, break off the tough stalks and discard, boil the tops in a large quantity of water for 3 to 5 minutes, depending on thickness, then drain and run under cold water to stop the cooking. Dry thoroughly. Blend the remaining ingredients by shaking in a jar. Pour over the asparagus, toss and serve. Other vegetables such as green beans work well with this dressing.