4906 St. Elmo Ave., Bethesda. 951-0670 Open Monday through Saturday 11 a.m. to 11 p.m., Sunday 4 to 11 p.m. Reservations suggested. AE, C, MC, V. Prices: Most items about $5. Complete dinner with wine or beer, tax and tip about $10 to $20 per person.

ONE'S FIRST EXPERIENCE with a new ethnic cuisine is something like one's first kiss: It's exciting, but on a scale of 1 to 10 it's hard to know whether to give it a 3 or a 9. What's missing is a frame of reference. That's why people's initial reaction to a new style of food is often indiscriminate acceptance. (If you'd never tried chicken soup, the stuff in cans might not taste bad.) Gradually as more of the new cuisine becomes available in more restaurants, people start developing their own yardsticks for judging it. Ask today's Chinese restaurant buff about the attributes of a good kang pao chicken or Peking duck and you might get a 30-minute lecture.

People are starting to reach that stage with Thai restaurants, now that there are enough of them around to permit comparisons. One of the newer ones is the Bangkok Garden, a place that should please even veteran Thai-food buffs. The setting is pretty, the food is mainly excellent, there are a few items not generally found elsewhere, and, although the prices are as low as in most Thai restaurants, the portions tend to be more substantial.

A word about appearance. The Bangkok Garden's predecessor was a combination Polynesian-Korean restaurant that had so many plastic flowers even the public phone was bedecked with them. A massive pruning seems to have taken place, with good results: There are freshly redone off-white walls, soft lighting, nice touches of color here and there.

For starters, the satay is top-notch, the skewered beef juicy and slightly pink inside, the flavors of char-broiling and marinade mingling nicely. (Inexplicably, the whole thing rests on a couple of slices of what seems to be Wonder Bread.) Hot and sour shrimp are hot indeed, zapped with chili pepper and Thai herbs, the shrimp wonderfully tender amid all that fire. Heat, but less of it, fires up a delightful appetizer called larb: minced beef with chili pepper, lemon juice, galanga and Chinese parsley. For a cool, mild appetizer, Thai salad with chicken and shrimp has a smooth, eggy dressing reminiscent of home-made mayonnaise. The only bad news in the appetizer department comes with the Bangkok Garden special beef, tough and ropey, and with the fried items: heavy egg rolls, mundane pork and crab meat cakes, crab-stuffed chicken wings with a leaden armor of batter.

If you're familiar with Thai food it should come as no surprise that the soups here are superlative, for it's in a soup that the Thai genius for mingling diverse flavors comes into its own. As in the several chili-laced lemon grass soups, where the hot-sourness is elaborated with ginger, garlic, and kafir lime leaf. Or, better yet, in a soup called kai tom ka, which has the added silkiness of coconut milk and galanga. But the real champ is an Asian version of bouillabaisse called Seven Sea Soup, a hefty m,elange of fish, scallops, shrimp and squid, all fresh and plump, in a delightful broth flavored with (at the very least) chili paste, galanga, kafir lime, ginger, lemon juice and lemon grass. With a bowl of rice, a large portion could serve a person beautifully as an entree.

Curries are another vehicle for showing off the Thai flair for interlayering flavors. And there's a most unusual one here called steamed fish curry, in which discs of fish with almost the texture of a souffl,e are wrapped in strips of cabbage and dressed with the most subtle of curry sauces -- delicate, unthickened, free of domination by cumin. Just as delightful is angel shrimp: huge, beautiful shrimp in coconut milk curry sauce with notes of anise, sugar, hot pepper and ginger.

Most restaurant shrimp is so poor these days that it's worth a visit here just to remember what it's supposed to taste like. If you want to recall good shrimp in its most pristine state, have Bangkok Garden shrimp, in which they're simply char-broiled and taste almost like lobster. (But if you don't want parts of the shrimp you're not accustomed to, specify that you want them trimmed.)

Also not to be missed are the whole fish dishes (as opposed to the fried filets, which we've found run-of-the-mill). Crispy fish with hot chili and garlic is a gem, the whole fresh flounder rubbed with minced garlic and pepper, quickly fried so

the skin is crackly and the interior firm and moist, and

served with just a bit of moderately hot, slightly sweet sauce.

Even better is fried spicy whole

fish, a crisp-skinned, perfectly

fresh sea trout covered with a

lovely shroud of vegetables and

sliced beef, and in a mild, gingery, softly pungent black bean

sauce. Not quite as formidable

but certainly unusual is yum pla

gob, oddly reminiscent of bacon,

in which very thin strips of fish

are fried crisp with scallions in a ginger-flavored, slightly tart sauce.

Soft-shell crabs have been less successful, swamped in too much of a thick, highly flavored sauce. And the noodle dishes are apparently a mixed bag. We've had excellent pad Thai, the rice noodles bitey with a piquant, vinegar-sugar flavor, and delightful crisp noodles, nearly the diameter of shredded wheat. But we found the noodles with broccoli a heavy mush.

What with the unusual items on the menu, we haven't mentioned the customary beef, pork, shrimp and chicken dishes with the "standard" Thai sauces. In brief, they're excellent -- the simple hotness of the chili and garlic sauce, the inimitable aromas of the Thai basil and garlic sauces, and (best of all) the complexity of the slightly sweet ginger root and onion sauce, flavored with black beans, tree ears and scallions. The biggest meat bargain is the Siam beef, a mountain of nicely marinated flank steak with vegetables in a mild, slightly sweet sauce. The fried rice is commendable, as are the vegetable dishes, lightly cooked and unmarred by thickened sauces.

The Bangkok Garden should rate high on anybody's scale. It has its flaws, but no one's a perfect kisser, either.