When Cafe Pierpont opened in the fall of 1986, I had little desire to try the food. While I respect the accomplishments of the Gastronomy partners, whose success is most notable at Market Street Broiler and Market Street Grill, I find their fare adequate yet predictable. I was also skeptical about their approach to Mexican cuisine.

I have a bias about the yuppification of any of the cuisines from the Third World, whether it is Asian or Mexican. Somehow eating dishes that come from a part of the world we have either ignored or exploited, at least until recently, with fellow diners whose tans originate from a salon rather than a dusty field, seemed incongruous, if not hypocritical.However, our interest in Cafe Pierpont was recently rekindled by some favorable reports about its consistency and its black bean soup, a dish I have relished in recent trips to less savory neighborhoods in New York City. It was also Election Night, and we wanted to partake in what we thought might be a last fling at upscale dining. Who better to go down to defeat with than people with telephones in their cars?

I have to report that all of my biases and prejudgments were wrong. The customers, including many prosperous downtown types, represent a cross section of the populace, from the bronzed beautiful people to the downwardly mobile middle class, like me.

The menu features some of the seemingly oddball variations one expects in watered-down ethnic restaurants such as seafood tamales and Mexican egg rolls ($3.95). We were a bit surprised when our pleasant and ethnic waiter, who hailed from Costa Rica, recommended the egg rolls rather than the more traditional taquitos. Filled with chicken, bacon and chiles, and served with a lively tomatillo salsa, these half-dozen little critters melted our apprehensions about eclectic preparations.

The black bean soup ($2.95), a flavorful, just slightly sweet blend of black beans punctuated with slices of green onions and a swirl of sour cream, was also a pleasing beginning to our meal. Other appetizers include guacamole and nachos (both $2.95), deep fried almond shrimp ($4.95), and taquitos. Complimentary warm corn chips, with both a tomato and red chile salsa, are also served.

We ordered two of the dinners, chicken fajitas ($7.95 for the half pound) and a halibut special ($9.95). The chicken was some of the best fajitas we have tried about town. The marinated chicken strips, mesquite grilled, are brought to the table sizzling with onions and cold garnishes of guacamole and pico de gallo, literally translated "rooster's beak" but actually a piquant citrus and yicama relish. We also improvised with the tomatillo sauce left over from the egg rolls.

The seafood special, another recommendation of our waiter, was a luscious piece of halibut, perched atop a platter of ancho sauce, an orangy red blend of red peppers and other spices. The fish was then covered with sauteed buttery bay scallops, also redolent with the mesquite aroma. A lovely presentation and an even better dish to eat. Both the entrees came with black beans; the fish portion also had a peppery rice side dish.

Other specials of the day included shrimp fajitas, mole verde, broiled red snapper, chicken flautas, passila peppers and green lip mussels. Regularly offered dinner entrees range from mesquite broiled steaks, chicken breasts and snapper (each $8.95) served with enchiladas, to various combination plates consisting of enchiladas, tacos and rellenos.

Chimichanga, grilled chicken with lime and cilantro butter, seafood and chorizo burrito, and a seafood as well as a vegetarian enchilada, round out the extensive bill of fare.

Cafe Pierpont is reportedly noisy, adding the din to dinner that characterizes the other Gastronomy establishments. Our weeknight visit found Pierpont about half full, just lively enough. The renovated interior is festive, highlighted by colorful folk art, enormous cacti, and spinning ceiling fans with trailing rainbows of ribbon. The high tin ceilings resonated with the sounds of the usual bustle of a busy restaurant, but not to the degree where we were distracted from our wonderful repast.

Rating: ****

Cafe Pierpont, 122 West Pierpont Avenue, 364-1222. Open for lunch Monday through Friday, from 11:30 a.m. till 4 p.m.; dinner served Monday through Thursday, from 4 p.m. until 10 p.m., till 11 p.m. on Friday and Saturday. Hours Sunday, 4 p.m. until 9:30 p.m. Major credit cards and checks with guarantee card accepted. Adjacent parking.