The Beltway is littered with one-sauce Tex-Mex chain restaurants, but rare is the restaurant that serves anything that would be considered familiar in Mexico City. Enriqueta's is the exception, and its menu is broad enough to encompass fresh fish as well as enchiladas -- but enchiladas with more interesting texture and complex flavor than in the ordinary Mexican taco joint. This is a good restaurant, a restaurant of character, that happens to also be Mexican.

Sauces are varied and delicate -- as well as pungent and fiery when the recipe warrants. Tortilla fillings are of quality ingredients, seasoned more intricately than the usual ranchero sauce; you can find an excellent mol,e and a piquant salsa verde among the enchilada and chicken toppings. There are beef dishes and shrimp dishes, and the only caution I would routinely offer is that chicken dishes tend to be overcooked.

The most enticing starter is mussels, which are rarely served so zestily spiced elsewhere. The melted cheese with chorizo also serves well as an appetizer.

Main dishes also offer surprises, especially among seafoods -- fish is carefully cooked and heightened rather than smothered by chili-spiked sauces, olives and such. The stuffed chili is studded with fruit and topped with a fruit sauce, which makes a sweet contrast to its heat. In all, Enriqueta's food is fresh and attractive, an interesting change from routine, and served in a small, crowded dining room decorated with bright colors so lively it suggests your being in the middle of a fiesta. 2811 M St. NW. 338-7772. L $6.50-$9.95, D $8.50-$11.50. L, D daily. AE, CB, DC, MC, V. Res sugg. Full bar.