At the end of this column every month, I ask readers to recommend restaurants that they think deserve a review. I take all recommendations seriously and try to eat at any place suggested, though I don't write about all of the nominees.

After an April review of dining in Alexandria's Del Ray neighborhood appeared, a reader chastised me for not including Los Tios Grill, insisting that it was much better than a nearby restaurant I had included.

After a couple of recent meals at Los Tios, I think that reader is right.I had passed by this brightly colored restaurant on Mount Vernon Avenue several times, but nothing had ever drawn me in. Now, I think, residents of the neighborhood may just have been trying to keep this gem to themselves.

In five years of reviewing local eateries, Los Tios is the most welcoming place I have eaten. Everyone is cheerful, and every person I dealt with told me how happy they were to have me as a customer and please, come back soon. This didn't come just from the server or the manager, but from the person who showed us to our seats and even the busboys.

The cheeriness extends to the decor, with walls a bright orangey terra cotta color, and a floor of large terra cotta tiles. There are touches of bright aqua on the exterior, and vivid paintings line the walls, which are also accented with large pieces of Mexican pottery.

German Mejia, who came to this country from El Salvador in 1983, opened Los Tios (which means "the uncles") in May 2004 in a small storefront. Mejia, a former manager of Guapo's Restaurant in Washington's Tenleytown, hired his brother, who formerly worked at Guapo's and Alero in Washington, as the chef.

When it opened, Los Tios had just 24 seats inside and a few more on a sidewalk patio. That changed last fall when Los Tios expanded into an adjacent space, adding a large dining room and more patio space. Now the restaurant seats 138 inside and 38 more on the patio. Still, you may encounter a wait if you arrive at a busy time, especially on the weekends.

The renovations aren't quite complete -- a 10-seat bar is planned to replace the small cagelike space that turns out the margaritas that seem to be a part of almost every table's order. And with good reason. The margaritas here are excellent, not too sweet and with a good taste of tequila, even the house brand. In addition, there is a good selection of upscale tequilas, and if you think you might drink two margaritas, go for the popular super margarita that arrives in a huge glass. (Most of the customers are neighborhood residents, many of whom walk to the restaurant.)

The chips and salsa arrive soon after diners are seated -- the chips are made from white corn and are thin and crispy. The homemade salsa is a little thin, but the fresh chunks of tomato and onions are savory without packing much heat.

The menu is long for both lunch and dinner. There are more Tex-Mex and Mexican dishes at lunch, more Salvadoran favorites at dinner.

Fajitas are the most popular dish, according to Mejia, and there is a broad selection that includes the usual steak, chicken and shrimp but also chorizo, barbecue ribs and various combinations of these, topping out with the parrillada, a giant assortment of all of the above, sufficient to serve three or four people.The long list of appetizers makes choosing difficult. A quesadilla, reinforced with jalapenos and grilled onions, and topped with pleasantly chunky guacamole, sour cream and pico de gallo, was flavorful and huge.

An unusual appetizer is the tamal de elote, which the menu describes as corn cakes. The dish is actually a corn tamale, with the typical corn exterior enclosing a corn pudding that was slightly sweet but not cloying and a perfect foil for the accompanying sour cream.

Chicken enchiladas were filled with shredded stewed meat, topped with melted cheese and accompanied by what the menu said was a tomatilla sauce but was actually a smooth but fiery green chili sauce. The refried beans aren't just mush -- most of the beans retain their shape, and the melted cheese on top accentuates the depth of flavor.

Two Salvadoran favorites are on the lunch and dinner menus: carne deshilada and plato tipico. The carne deshilada is shredded beef served with eggs and homemade corn tortillas, and the plato tipico is scrambled eggs with beans, fried plantains and the tortillas.

Salvadoran and Mexican dishes dominate on the dinner menu. Among the favorites are bistec encebollado -- a flavorful and tender skirt steak topped with grilled onions and served with unusually good white rice -- and camerones a la plancha, fresh briny shrimp grilled, topped with cilantro and served with black beans and white rice.

Los Tios's version of tres leches cake is a three-inch-high square of light yellow cake saturated with the usual whipping cream, evaporated milk and sweetened condensed milk. It's too sweet for me to finish a whole portion.

Sopaipillas -- fried puffs of dough -- are served with honey, chocolate syrup and vanilla ice cream. They were the only disappointment; the dough was tough. And besides, I'd prefer them plain.

--Nancy Lewis (June 28, 2007)