TO THE tourist who brings a Western palate to a Bangkok hotel or restayrant table, Thai food can be a not-so-good approximation of what they're serving at the Gopher Prairie Hoilday Inn.

To the grass-thin Cambodian refugee standing in line for the weekly United Nations food distribution in a camp on the border of what is now Kampuchea, it translates as a family ration of eight pounds of rice and three cans of tuna.

To the ordinary Thai citizen, it means a happy and comparatively ample melange of fish, shrimp, chicken and pork, served with rice and made the more enticing via coconut, limes, garlic, peanuts, coriander, ginger and hot peppers.

It also means an Edenic array of fruits that don't often make their way to Western supermarkets. And don't taste the same if they do.

At this season, the last of the mangoes are flaunting their pine-edged sweetness. Papayas, of course, and bananas of extraordinary flavor intensity.

But the stars of the show are the rambutans and mangosteens. The rambutan looks like a pink-speckled chestnut burr on the outside. Within, there's a pale fruit that makes prying it open worthwhile. The mangosteen operates on the same principle. A small, round eggplant sort of thing on the outside, it has at its center what looks like a particularly pearly head of garlic. The delicately flavored juiciness is enough to make anybody want to emigrate in spite of the Bangkok traffic.

These wares are most splendidly displayed in the floating markets along the canals, or klongs, that give Bangkok its Venetian aspect. There aren't as many of them as there used to be -- drained and paved over with the growth of the city -- but enough to accommodate a great many of the graceful boats that serve the purpose of supermarket bins in Thailand.

Whether it's Thailand's uniquely succulent pork that's featured or an assortment of fresh coconuts and pineapples, each boat is a display piece in itself. Propelled by a slender woman wearing a long, bright skirt and a distinctively shaped straw hat, each looks as though it belongs at the center of a banquet table.

The visitor is easily charmed into drinking the translucent milk from a coconut carved open on the spot. A little disappointing to the taste buds, perhaps. Oh, well, so much for picturesque experiences. And the coconut does wonderful things once it's in the curry. Besides, as something to drink, coconut milk is considerably better than the colas and soda pops that seem to be saturating the Orient these days.

Happily, there's a good Thai beer to soothe some of the effects of all the ginger and chilies. Sometimes. When the pepperiness reaches a Szechuan intensity, the beer can seem like first aid.

The Chinese element, of course, is only one strand in the cultural fabric that makes Thai cooking what it is. India is in there too, and France, which for so long controlled neighboring Indochina, has added its subtlety to the bouquet.

For those who would like to duplicate the special pleasures of Thai cooking in a Western setting, there are a certain number of insoluble problems. You aren't going to be able to include lotus buds in the vegetable lineup, or any number of other local roots and shoots.

On the other hand, chicken is chicken, shrimp is shrimp and pork is what it is even if the Thai variety has a quality superior to almost any other. And the spice importers have placed almost any flavor enhancer within almost any American's reach.

This holds particularly true for Washington area cooks. The Oriental community in Washington and northern Virginia is big enough to support numerous grocery import operations. You can find fresh coriander and lemon grass at Oriental food stores all over the area. Ginger, dried coriander and the rest go without saying. Speak up if you can't find lotus seeds. Let pineapple and banana make up for the lack of rambutans and mangosteens.

Probably the most translatable and universally congenial Thai dishes are the lemony shrimp soups and the coconut-meat mixtures. Here's an Americanized cross-section of the possibilities.

It should be noted that American packaged coconut is not suitable for most meat, fish or poultry recipes. It is too sweet for any but dessert uses. Unsweetened coconut, bought in a health food store, or freshly grated coconut are more in the spirit of Thai culinary art. Combined with cream or yogurt, they approximate the Thai effect with relatively little violence to the purity of the original.

A few further hints: Follow the Thai rule of not salting or applying oil of any kind to the rice. Yes, it cooks wonderfully when slightly stir-fried with salt, garlic and salad oil the way the Brazilians do it. But it should be bland for a proper counterpoint to the spiciness of the rest of a Thai meal.

Make use of fresh cucumbers, of which there is an ample supply right now, even for those who are neither gardeners nor friends of gardeners. Their cool, crisp effect, like that of radishes and water chestnuts, which Southeast Asians also love, offsets the heat of a spicy main dish without nullifying it.

Don't consider the coriander optional. It gives many Thai dishes their greatest distinction. Look to the Oriental groceries until you can grow your own.

SHRIMP, PORK, CHICKEN AND CUCUMBER SOUP (4 to 6 servings)

1 clove garlic, crushed

2 medium onions, minced

1 teaspoon fresh coriander leaves, minced, or 1 teaspoon ground coriander

2 tablespoons oil

1 cup raw or cooked pork, slivered

1/2 cup raw or cooked chicken, slivered

1/2 cup cooked shrimp

2 teaspoons soy sauce

4 cups chicken stock

1/2 cup sliced fresh mushrooms

1 cup diced raw cucumber

2 eggs, beaten

2 tablespoons chopped parsley

Saute' garlic, onions and coriander in oil until onions are translucent. Add pork, chicken and shrimp and stir-fry with soy sauce until meat is brown. Stir in stock and simmer 15 minutes. Add vegetables and bring to a boil. Add eggs gradually, stirring constantly. Garnish with parsley.

SOUR SHRIMP SOUP (4 servings)

4 cups chicken stock

2 tablespoons lemon juice

2 tablespoons lime juice

1 teaspoon soy sauce

1 tablespoon fresh coriander leaves, minced, or 1 teaspoon ground coriander

Pinch hot red pepper

1 pound shrimp, shelled and deveined

1 cup minced scallions

Combine all ingredients except shrimp and scallions. Simmer 10 minutes. Add shrimp and simmer 5 minutes longer. Garnish with minced scallions.

CURRY PASTE FOR MEAT (Makes enough for a curry serving 4 to 6 people)

2 tablespoons anchovy paste

1 teaspoon freshly grated nutmeg

1/2 teaspoon ground cloves

1/2 teaspoon ground cardamom

1 teaspoon mace

1 tablespoon ground coriander seeds

1/2 teaspoon ground caraway seeds

1 teaspoon paprika

2 teaspoons white vinegar

Combine all ingredients and mix well. Substitute for curry paste or powder to taste in any lamb or beef curry recipe.

POULTRY AND SEAFOOD CURRY PASTE (Makes enough for a curry serving 4 to 6 people)

1 tablespoon ground coriander

1 tablespoon ground caraway seed

2 tablespoons anchovy paste

Pinch cayenne

1/2 teaspoon freshly grated nutmeg

2 teaspoons vinegar

Combine all ingredients, mixing well. Substitute for curry paste or powder to taste in any chicken, fish or shrimp curry recipe.

CHICKEN IN COCONUT CREAM (4 servings)

1 frying chicken, cut in serving pieces

2 tablespoons safflower oil

1 large fresh coconut

Pinch pepper

1 teaspoon sugar

1/2 teaspoon salt

1 teaspoon anchovy paste

2 dried red chili peppers

1 teaspoon ground caraway seeds

1 tablespoon fresh coriander leaves or 1 teaspoon ground coriander seeds

Juice of 1/2 lemon, plus grated rind of 1 lemon

1/2 cup heavy cream

4 tablespoons peanut butter

Monosodium glutimate

4 tablespoons peanut butter

Rice, for serving

Saute' chicken in safflower oil until golden brown and almost cooked. Grate coconut and simmer in 2 cups water for 20 minutes. Let stand until cool. Strain coconut pulp, pressing down to extract all liquid. Add chicken and seasonings to liquid and simmer until chicken is done. Remove chicken and reduce sauce by half. Stir in lemon, lemon rind and cream along with peanut butter. Pour over chicken and serve with rice.

Note: A variation uses cinnamon and dried mint along with the other spices.

If rice is synonymous with food in the Thai language, fish is almost equally important. It's generally simmered with ginger and mushrooms, or onions with perhaps a bit of minced scallion and soy sauce to vary the impact.

Here's a canape that reflects its popularity.

THAI FISH CANAPES (Makes about 12 canapes)

3 tablespoons cooked fish, preferably bland and white

1 clove garlic, crushed

1 teaspoon brown sugar

2 tablespoons lemon juice

Few dashes hot pepper sauce

1 1/2 teaspoons anchovy paste

2 tablespoons minced green olives

1/2 teaspoon each lime and orange rind, grated

Flake fish and combine with other ingredients. Serve on slices of peeled cucumber or bread rounds.

GOLDEN THREADS

6 eggs

1 cup sugar

3/4 cup water

Separate eggs and set aside whites for other uses. Beat yolks until thick. Boil sugar and water together to form a syrup. When syrup has thickened slightly, begin pouring beaten egg yolks -- through a cone of aluminum foil with a small opening -- into the syrup, which should be still gently bubbling. The yolks will form threads, which should be allowed to cook until a bit stiff. Remove with a slotted spoon and set aside on absorbent paper. Continue until all the egg yolks have passed through the sieve. Use as topping for fresh fruit combinations or top with a mild-flavored ice cream.