LAURIOL PLAZA -- 1835 18TH ST. NW. 202-387-0035. Open: for lunch Monday through Friday 11 a.m. to 3 p.m.; for dinner Monday through Thursday 3 to 11 p.m., Friday 3 p.m. to midnight, Saturday 11 a.m. to midnight, Sunday 11 a.m. to 11 p.m. All major credit cards. Reservations accepted at lunch only. Separate smoking area. Prices: appetizers $2.50 to $8.95; lunch entrees $5.95 to $16.50; dinner entrees $6.95 to $16.50. Full dinner with drinks, tax and tip $20 to $40 per person.

From the street Lauriol Plaza looks nothing like a Spanish or Tex-Mex restaurant. When the sidewalk tables are gone and the blue umbrellas furled, you might not notice this giant brick box is a restaurant at all.

Inside, though, it looks like a restaurant and more. A mural of a Spanish fiesta covers one wall of the bar; the interior beyond is cool and urbane, all matte-black metal and white walls, with woods in four tones forming the curved ceiling and stair rails. The expanse is magnified by windows as tall as most of the neighborhood's entire buildings.

Sit on the balcony, and you'll see 18th Street from a new perspective. Sit on the street level, and you'll feel keenly that you are in a modern capital, where space is lavish and understatement is art. A small bouquet of flowers and a tiny flickering red glass globe are enough to decorate the white linen tablecloths.

Lauriol Plaza is a Tex-Mex restaurant where you wouldn't feel out of place wearing a little black dress and a string of pearls. It's immense and intimate, sophisticated and casual, with a Rube Goldberg sort of tortilla maker adding a touch of industrial charm.

It's also, at least for now, a madhouse of diners waiting for tables. Lauriol Plaza takes no reservations at dinner, and even with 330 seats the waits can be long. While the designer has cleverly shielded the dining room from the noisy bar and holding area, for the first stage of your evening at Lauriol Plaza, you need to be prepared for battle.

A cadre of hospitable young women organizes the waiting list. They do as well as can be expected -- better, in fact. But they can't make the standing around pleasant.

Waiters, too, have a big job. In a new restaurant this size, it's no surprise that some of them are amateurish. If you're assigned one of the older, more experienced ones, your dinner will be a breeze. I'd return just for the witty good cheer of our first waiter, who took four different margarita orders (with salt/without, blended/on-the-rocks, one nonalcoholic) and delivered every variation to its rightful owner. He anticipated our needs, brought sharing plates when he saw us passing ours, and was always around when we needed him. He took the time to explain the workings of the tortilla maker and brought us warm tortillas to try, even added some to our doggie bags. (Note how many people leave with doggie bags. Note how large the portions are. Order accordingly.) Subsequent waiters haven't had his finesse, but they've done the job efficiently.

On my second visit, I was tempted to order nothing but a drink. By now I knew that there's a reason someone shows up in the dining room several times an hour with a plastic bin the size of a small car, ready to refill the gigantic trough of freshly fried tortilla chips. These are some of the best chips anywhere, thin and crisp, with just enough salt and not too much grease. The salsa is warm to the touch and on the tongue, a near-liquid puree fragrant with ground chilies, onions, peppers, tomatoes and spices. Together, they're a powerful temptation. If your first course is slow in coming, you might get so full you'd consider moving directly to the doggie bag stage. And if you've had more than one margarita -- big, strong and eyelash-curling-tart ones with no unwelcome taste of chemical mixes -- you might not even be able to move.

This shift upscale and up the street has breathed new life into Lauriol Plaza's kitchen. The food is as good as I remember it from the restaurant's early days. It's still as good a bargain, too, considering the portion sizes.

This is not groundbreaking cooking. It's the standards -- tacos, enchiladas, fajitas and a few Spanish dishes -- done in a straightforward, hearty style. The specials stretch the boundaries a bit, and they've been among the best dishes. One night the silkiest rockfish, perfectly moist and fresh, was topped with shrimp, scallops and mushrooms in a light, clear sauce. Even the vegetables -- carrots and green beans -- were flawlessly cooked. The shellfish were pretty tasteless, as shrimp and scallops tend to be in all but the fussiest restaurants nowadays, but otherwise it was an entree of great finesse. Another special was braised tongue, the meat so soft a fork would cut it, in a delicate, unthickened tomato sauce.

Lauriol Plaza is one of those rare restaurants where the entrees tend to be better than the appetizers. The latter are routine: Quesadillas thick with cheese and suitably bland. Tamales moist and one-dimensional, tasting of little but corn. Seviche is big and refreshing, though barely spiced with anything but lemon. Shrimp are smothered in garlic, which masks their dullness, and mussels are plump in their sherry and ginger sauce, but fade in all this Tex-Mex company. Nachos are nachos. Soups are slapdash.

Those free chips and salsa remain the best appetizer.

Then you can go straight to the entrees. Fajitas are piled with smoky, well-marinated meat; they're more satisfying than the restrained enchiladas. But the Spanish and Latin American dishes have more character than the Tex-Mex. Even with unremarkable seafood, the mariscos saltado is a playground of tomatoes, onions, chilies, cilantro and fried potatoes; the paella has a briny intensity. Masitas de puerco is mild, comforting chunks of pork with an undertone of orange. Pollo asado, even better, is a half-chicken well browned and buried in dark fragrant onions. Whatever you order, there's no danger of going hungry, given the glistening mounds of rice and bowls of inky black beans. If your platter doesn't come with maduros (ripe plantains) or tostones (the lightest of starchy fried green plantains), make them your appetizers or side dishes.

The few desserts represent the tropical classics, from guava paste to Key lime pie, including a remarkably unseductive flan. There's one crowd-pleaser, cajeta: ice cream rolled in coconut and nuts with caramel. To balance the chips and salsa, no doubt.

Turning Tables

Restaurants have reason to be nervous about no-show reservations, which cost them considerable revenue. But the cure threatens to get worse than the disease. David Bouley's new Danube restaurant in Manhattan asks that you reconfirm your reservation three days ahead, then again the day of your reservation. At least the staff isn't totally shameless about this excess: When the reservationist heard my disbelief, she laughed sympathetically.

A more welcome trend that's moving from Manhattan to D.C. is restaurants taking a clear stand on cell phones. Melrose, at 24th and M streets NW, for example, requests on its menu, "Please use cellular phones in the telephone area." -- P.C.R.