THAI FOOD looks like one of the biggest growth industries in the Washington area, and no wonder. Having developed their cuisine amidst and abundance of fruits, vegetables and seafood, the Thai people have mastered the art of serving natural foods, Oriental style -- stir-fried and barbecued, mainly -- but with a unique lightness, sparkle and variety.

Thai chefs try to achieve a balance in each meal between the five main flavors: bitter, salt, sour, hot and sweet. Red and green chili peppers give much Thai food its characteristic pizazz and color. Saltiness is generally provided by nampla (a thin brown sauce akin to the Vietnamese nuoc mam , drawn off barrels of salted and fermented fish or shrimp) and kapee (fish or shrimp paste). These flavoring agents no doubt sound unappetizing, but it's amazing how unfishily they transform the food they season -- particularly in combination with lime juice (another common Thai ingredient) and the fresh herbs found in so many Thai dishes: coriander (cilantro), basil and mint, as well as scallions and garlic.

Although you may find it worth our while to buy the herbs at the National Cathedral greenhouse and grow them on your windowsill, you can find some of these ingredients in some supermarkets and health food stores. Other ingredients essential to Thai cooking, such as lemon grass and citrus leaves (makrud ), can be purchased only in special Oriental markets. Fortunately, stores selling Thai ingredients abound in this area.

It's amazing that Thai ingredients are so easy to find in the Washington area, considering that when Charles E. Tuttle published "Siamese Cookery" by Marie Wilson in 1965, the author had to suggest such radical substitutes as sour cream for coconut milk, parsley for coriander leaves and radishes for red chili peppers. East and West had not yet met in local supermarkets. You can find more authentic Thai recipes in the following three cookbooks:

"Pacific and Southeast Asian Cooking" by Rafael Steinberg (Time-Life Books, $12.95): Fewer than 20 pages and five recipes in this "Foods of the World" title are devoted to Thai food, but the photographs (including an artfully carved pineapple with instructions on how to recreate it) are mouthwatering.

"Flavors of Southeast Asia: Recipes from Indonesia, Thailand, and Vietnam" (101 Productions, paperback, $5.95): Jeffrey Davis wrote the section on Thailand included in this book, and the recipes we tried were relatively easy to make, tasty and (according to Thai visitors we tried them on) fairly true to the original. This $6 paperback is a good buy for people who want to dip a toe into Thai cooking without taking the full plunge.

"The Original Thai Cookbook" by Jennifer Brennan (Richard Marek Publishers, $12.95): Just published, this 320-page cookbook may tell you more about Thai cooking than you want to know, but the recipes we tried were extremly good and authentic. What the book lacks in style (charm, mainly) it more than makes up in recipes, though squid is obviously not the author's forte. (In our experience, squid should be cooked no more than 1 or 2 minutes to remain tender, particularly for a squid salad. She suggests boiling it for an hour and a half to two hours.) Nevertheless, this is a great gift book for cookbook collectors and fans of Thai food. LEMONY SHRIMP SOUP (Kaeng Tom Yam Kung )

This delicious and unusual soup is one of Thailand's favorites; it's also one of the most exquisite looking dishes you're likly to serve. The pinkness of the shrimp floating in the light broth is set off by the green of scallions and coriander and the red strips of chili pepper. 1 1/2 pounds medium-size uncooked shrimp (21 to 25 per pound) 2 1/2 quarts water 6 small makrut (citrus) leaves 1 tablespoon dried lemon grass sticks, cut into 1-inch lengths 1/3 cup strained fresh lime juice 1/3 cup fish sauce (nam pla) 1/4 cup finely cut fresh coriander leaves 1/4 cup scallion tops, thinly sliced and cut into 1 1/2-inch lengths 12 fresh hot red chili strips, each about 1/8-inch wide and 1-inch long

Shell the shrimp carefully, leaving the tails attached, and devein. Wash and dry with paper towels.

In a heavy 4- to 6-quart casserole, bring the water to a boil over high heat. Drop in the makrut and lemon grass, and boil uncovered for about 10 minutes, or until the leaves become somewhat yellow.

Stir in the lime juice and fish sauce and boil the soup for 5 minutes more. Reduce the heat to moderate, drop in the shrimp, and cook for 4 or 5 minutes, or until the shrimp are firm and pink. Add the fresh coriander leaves scallion tops and red chili strips, and taste for seasoning. Serve at once. Adapted from "Pacific and Southeast Asian Cooking" GHIN NA REE'S SPICY SQUID SALAD (2 small servings)

None of the cookbooks I found give a satisfactory recipe for this wonderful dish, so I asked the owners of Ghin Na Ree (a Thai restaurant in Arlington).

For 1/2 pound squid, prepare the following dressing: 2 tablespoons fresh lime juice 1 to 2 tablespoons fish sauce (nam pla) 2 chopped scallions 1 or more red serrano chili peppers, cleaned, seeded and cut into thin strips

Clean squid, removing surrounding membrane, ink sac, cartilage and eye section. If it has a fishy smell, soak it for a few minutes in plain vinegar (though I rarely find this to be necessary).Cut it into 1-inch squares or rings, including the tentacles, and drop the cleaned squid into enough boiling water just to cover it. When the water comes to a boil again, let the squid cook annother minute, then remove from the heat and immediately drain. Toss squid with the dressing and refrigerate.

Proportions of the fish sauce and chili peppers should be adjusted to suit your taste for saltiness and spiciness. To some people, one chili pepper is mere decoration. Fresh lime juice is the important ingredient in this recipe -- it produces a fresh taste that even squid-resisters often find irresistible. THAI LIMEADE*NAM MANAO (Makes 12 to 16 glasses)

Thais tend to prefer this cool, refreshing lime drink made with salt instead of sugar, but I find that the inclusion of both makes for a perfect effect. 6 fresh limes 1/2 cup sugar 2 1/2 cups boiling water 1/2 teaspoon salt 12 ice cubes

Roll the limes on a cutting board, using hard pressure with the palm of your hand. This loosens the flesh and releases the juice more readily. Cut the limes in half and squeeze the juice, minus seeds and pith, into a jug. (They should yield approximately 1 cup juice.) Reserve the squeezed lime rinds, placing them into another jug, and cover them with the sugar. Pour the boiling water over the sugared lime rinds and allow it to steep for 15 minutes.This infusion draws the aromatic oil from the skin. Do not over-steep or the brew will become bitter. Add the salt and stir thoroughly. Strain the warm liquid into the jug containing the lime juice. Add the ice cubes and refrigerate. When serving, fill each glass with at least 4 additional ice cubes and pour in the limeade. LARB* (Steak Tartare, Thai-Style) (2 to 4 servings as an appetizer)

The Thai version of steak tartare has a decided hotness to it. This version from "Flavors of Southeast Asia" works nicely (even if you grind the beef in a food processor), but Thai cooks I've watched often heat the rice and dried chili peppers together in a small pan, then toss them into the blender, thus making their own rice powder and chili powder at the same time. If the taste is not quite right, try adding a little more lime juice (or, for saltiness, nam pla ). 8 ounces beef tenderloin, sirloin or round, or tender chicken breast meat 2 teaspoons long-grain white rice 1 tablespoon coarsely chopped fresh peppermint leaves (optional) 2 teaspoons coarsely chopped fresh coriander 1 teaspoon finely shredded red onion 1 teaspoon scallion Juice of 1/2 medium lemon or lime (or more) 2 teaspoons fish sauce (nam pla ) 1/4 to 1/2 teaspoon Asian chili powder Chilled romaine lettuce leaves

On a cutting board, chop the meat very fine with a cleaver. Place the meat in a strainer and immerse in a pot of simmering water for 30 seconds for the beef, 1 minute for the chicken. (It is important that the chicken be cooked through, so this step may take even longer than 1 minute. Leave the chicken in water until all redness has disappeared.) Remove the meat from the strainer and drain well; set aside.

Put the rice in a small pan and, shaking the pan constantly, place over medium heat about 3 minutes, or until the rice is opaque and just beginning to brown. Put the toasted rice in a mortar or in a blender container and grind until it is the texture of fine sand. Combine the ground rice, reserved meat, peppermint leaves, coriander, red onion, scallion, lemon or lime juice, fish sauce and chili powder and mix well. Taste and adjust seasonings. chill and serve with lettuce leaves for each diner to fill with the meat mixture and eat out of hand. CLAMS FRIED WITH BASIL (hoi Paht By Holapa ) (2 servings) 1 pound small clams in the shell, such as steamers or butter clams 2 tablespoons peanut oil 2 to 4 fresh green chili peppers, coarsely shredded 2 garlic cloves, crushed 1/4 cup coarsely chopped fresh basil, or 2 tablespoons crumbled dried basil 1 tablespoon fish sauce (nam pla ) 1/2 teaspoon dark soy sauce

Scrub the clams well and place in cold water to cover for 20 minutes. Drain and set aside. Heat the oil in a wok or skillet, add the chili peppers and garlic and stir-fry for 30 seconds. Add all remaining ingredients, stir well and cover. In about 30 seconds, the clams will begin to open, releasing their juices and completing the gravy. When all the clams have opened, remove from heat and serve. (Discard any clams that fail to open.) Adapted from "Flavors of Southeast Asia"