Open Sunday through Thursday, 11 a.m. to 10:30 p.m.; Friday and Saturday, 11 a.m. to 11 p.m. Reservations accepted. AE, MC, V. Prices: Lunch and dinner appetizers average $4, main dishes average $4 to $6.

It is safe to assume that this is the only restaurant in the Washington area serving Mud Fish Sauce with Vegetables. Certainly the only one serving it in a half-timbered dining room with Tiffany-style lamps.

But that's not what should take you to the Bangkok Gourmet; in fact, the waitress isn't likely to let you order Mud Fish Sauce with Vegetables anyway, and her reluctance is justified. What should draw your interest is an interesting variety of Thai dishes--with daily specials such as rabbit curry or spicy lamb with eggplant--served by an extremely solicitous staff, at prices low enough to allow risk-free experiment.

As on any exotic menu, for your taste there will be hits and misses. (And if you don't like the taste of fresh coriander you might find only misses.) Furthermore, as you might expect on a menu where most main courses are about $4, you are going to find the food rather inelegant, with chicken hacked into cubes rather than carefully boned and diced, and small portions of meat swimming in curry sauces rather than meat outweighing the liquid.

Dining at the Bangkok Gourmet takes an open mind, one ready for blazing spices (though most of the dishes are not very hot unless you request them so) and unfamiliar combinations of seasonings--a recurrent sweetness of coconut milk and tartness of lemon, for instance.

The dining room has an honorable history, having been Charda's, a pleasant Hungarian restaurant that left its mirrored walls and brown tablecloths. Whatever the decor lacks, though, the hospitality of the service makes up. Depend on the waitresses to guide you through the menu's mysteries, to change plates as new courses require it, to introduce you to Thai food if you are unfamiliar with it.

Appetizers are highlights of Thai menus, and Bangkok Gourmet has 16 choices at dinner, in addition to nine soups. Most are salads that are intriguing mixtures of hot and cold, hot and tart, hot and bland. Definitely hot. And definitely delicious. Charcoal-grilled beef, for instance, is crusty slices of meat coated with a crunchy and tangy spice mixture, tossed with raw onions, lots of lemon and hot peppers and mint. Sinewy meat but irresistible flavor. There are also salads with pork and shrimp. But for contrast, try sat,e, skewered meat also rubbed with spices, this time subtly curried, then grilled on sticks and accompanied by an excellent room-temperature sauce both faintly sweet and faintly hot and based on peanuts; alongside is the inevitable and wonderful vinegar-and-chile- seasoned cucumber salad. While Bangkok Gourmet seasons its food deftly, it sometimes cooks it less well. Thus the ground shrimp cakes, tod mun, were greasy and the shrimp and crabmeat wrapped in bean curd skin was compacted and chewy. Mussels were just dreadful--shriveled and tasteless.

Since Washington's first Thai restaurant opened, there are those of us who cannot live without chicken-coconut-galanga soup. And I have tasted none other as good as Bangkok Gourmet's. Its broth is red-gold, fairly fiery with chiles but tamed by the coconut-milk sweetness and livened with just enough coriander that it doesn't dominate. The chicken pieces are moist and tender, and the interplay of flavors is memorable.

Main dishes go on for pages, most of them variations on themes of garlic with pepper, curry, Thai basil and oyster sauce. At dinner they have been served with rice spooned from an elaborate silver bowl, and there are dishes that look quite elegant: Steamed Sliced Fish a la Bangkok is discs of fish wrapped in cabbage leaves and stuffed with a coral-colored paste boldly flavored with garlic and coriander. The gold-and- white fish cakes are topped with shreds of red, and the whole looks lovely and exotic. It tastes strange and not particularly appealing, however, if you are expecting anything like a typical steamed fish. Lobster with oyster sauce also looks impressive, but the sauce was soupy with no definition of flavor, just dark and damp.

We had better success with less elegant main dishes. Chicken with garlic and black pepper was the best of the main dishes, the diced meat tender and juicy in a smooth light wash of sauce with the delicate sweetness of gently cooked garlic. It was a subtle and wonderful combination of flavors, nearly as good with shrimp, though the shrimps themselves had grown a bit soggy. Beef curry with potatoes and peanuts was more robust, a soupy bowl of brick-colored and coconut-flavored curry. Hardly peppery, it was complex and aromatic. Spicy Lamb with Eggplant looked distinctly unappealing, being a clump of gray and black diced bits. But its flavor was zesty and earthy from branches of Thai basil.

Bangkok Gourmet has had on its lunch menu a delightful combination of noodles in a sweet dark broth topped with roast duck slices that have been seasoned with five-spice powder and coriander. A mite too sweet, perhaps, but a savory and filling dish at a low price. At dinner, though, the roast duck has been left fatty and has hung around to grow limp and dry, a poor relation to the luncheon duck dish.

Bangkok Gourmet has some good surprises when it comes to dessert. We missed the lichee ice cream, but did find homemade cantaloupe ice cream, coarse-textured but with a lovely fragrance. And coconut custard was fragile and eggy, fine stuff.

In all, the menu at Bangkok Gourmet provides culinary adventure at some of the lowest prices still to be found in the Washington area.