The Brasserie makes it perfectly clear that its mission is to serve fine food, in an environment just comfortable enough to be a pleasant backdrop. But the food is the focus.

The menu has blossomed over the years so that within a fairly small selection are more intriguing choices than some of the longest of menus. To start there is a fish soup under a puff-pastry hat, but then there are likely to be a half-dozen seasonal soups. Appetizers include salmon smoked in-house, multiflavored pastas in a salad, and a vibrant salad of chicory, duck and bacon with raspberry vinaigrette. Main dishes include such luxuries as lobster with garlic butter, profiteroles of crab meat, monkfish with orange, duck breast with cassis, veal with crab and liver with shallots or raisins. Then there are such daily specials as saute of lamb with homemade noodles, and crab cakes light in texture and broiled rather than fried, seasoned with red bell peppers inside and as a sauce. At lunch there are various deep-dish quiches. In season the seafoods and vegetables are chosen to reflect the best of the market.

La Brasserie's ambitiousness also extends to desserts. Here you will find outlandishly rich creme brulee, and sometimes even a hot fruited version. There are berry tarts and berries glazed with caramel or custard; and chocolate appears as a deeply intense marquise with coffee custard sauce or as mousse white or dark.

La Brasserie has the easy good nature of its Parisian namesakes, but food that vies in elegance and complexity with the city's gastronomic palaces. 239 Massachusetts Ave. NE. 546-6066. L $6.50-$9.50, D $10- $20. L, D daily. AE, D, MC, V. Res sugg. Full bar.