During lunch, much of the city's local power center moves out of the District Building down Pennsylvania Avenue to J.J. Mellons, where the mayor, several City Council members, high-ranking city officials, developers and labor leaders often gather to talk about issues, sign contracts and work out compromises over the wine glasses.

Mayor Marion Barry often uses one of the small dining rooms off to the side for his working lunches and orders a dish made specially for him, dubbed "the mayor's salad." It's up to owner and maitre d' Joe Malhotra to direct the traffic in the main dining room, which often includes City Council members Polly Shackleton, John Ray, Betty Ann Kane and Charlene Drew Jarvis; City Administrator Thomas Downs, and M. Carl Holman, president of the National Urban Coalition.

What Fran O'Brien's in Annapolis is to the Maryland General Assembly, and Maxine's in Richmond is to the Virginia General Assembly, J.J. Mellons has become for the District building -- a favorite meeting ground.

With its strategic location a block east of the District Building and across from the Presidential Building, home of several city departments, the school board and top school administrators, Mellons has become a natural magnet for local power lunches.

"You can tell what's happening in this city by who's having lunch with who," said owner Malhotra, "I see people hammering out business before I read about it in the paper."

When Mellons, with its gourmet menu, carpeted dining room, plush private alcoves and white linen swathed tables, opened two years ago, it resembled a duded-up Easterner who had just arrived in a Western frontier town.

Outside the front door, Pennsylvania Avenue was a baffling maze of planking, huge drainage pipes and noisy heavy-construction equipment. It was difficult for customers to find their way in, and business was spotty.

"I wanted to hand out hard hats to my customers, to safeguard them from all the construction," said Malhotra, who has been in the restaurant business for more than a decade. "But the city administrators, City Council people and every possible developer came to patronize us, and they always brought others along, which generated more business."

Located on the bottom two floors of the office building at 1201 Pennsylvania Ave. NW, Mellons was the first deluxe restaurant to result from the refurbishing of Pennsylvania Avenue and the old downtown that was then awash in fast food places, grimy bars and small grim restaurants with lackluster menus, usually headed by hamburgers.

"It took a lot of courage to open on the avenue . . . . It was a big risk, and it was a big step which set the pace for other developers," Kane said.

The council member, who said she lunches at Mellons two or three times a week (and enjoys the fresh salmon grilled with lemon and butter), said she does "a lot of business . . . or rather people can do business with me."

District chief labor negotiator, Donald H. Weinberg, said he cannot remember where he ate before Mellons. "I don't think I ate at all."

He added, "We have signed plenty of contracts in here; I'm talking about the big ones," said Weinberg, "like with the firefighters and at least five of the white and blue collar contracts . . . . And talk about negotiations; oh, well -- they just never stop."

Malhotra, 34, who is Indian, is no stranger to the city's power elite. He was once part-owner in Joe and Moe's on Connecticut Avenue NW. He tries to create an atmosphere in which people feel comfortable and where people can eat and do business. He instructs his waiters to be "cordial and familiar" to patrons "but not chummy," he said.

The food is tasty, the portions plentiful; and the prices speak of expense accounts. For example, the medallion of filet mignon with a claret brown sauce costs $10, the fresh calves liver with onion, $9.50, and two chicken breast dishes are $9 each. Fresh strawberries are $3.50, and expresso is $1.50. Lunch for two without dessert averages $25.

Last month city health inspectors closed the restaurant for a day because of unsanitary food storage, ineffective roach control and an inoperable employe hand basin, according to city records. Malhotra said the inspectors came in the evening and the restaurant opened on time the next morning.

Like other successful restaurateurs, Malhotra is gracious to his customers, remembers names of regulars and keeps up with the news.

"It's not unusual for the mayor to call right before he comes over," Malhotra said. "He may ask for a favorite table or the private dining room for an important meeting or just about anything. And nine times out of 10 I will know what's going on before he even gets here."

Sometimes a meal is not for business but for pleasure. Last week, John Ray sat drinking a light beer with two staff members as they celebrated his victory a few hours earlier in gaining tentative passage of a bill that would make major changes in the city's rent control laws.

While the power elite gathers in the dining room decorated in muted colors, some people from the surrounding federal and city offices prefer the more relaxed atmosphere in the sunny casual dining room upstairs, which features a long wooden bar, brass fixtures and a lighter and less expensive menu that includes salads, sandwiches and daily selection of entrees priced between $5 and $8.

City Administrator Downs, a regular at Mellons, was recently surprised on his birthday with a party from his staff and a piece of cake and balloons from Mellons.

"I don't know how they found out about" the birthday, "but it's that kind of touch that means a lot," Downs said.

"Besides, the food is fantastic," he added.