Romeo Garcia concocts pasta delicacies. Rafael Antonio Diaz is an expert in the ways of tempura and yakitori. And Jose Vasquez's tour de force is his chocolate mousse.

All three are cooks in Washington area restaurants and all are Salvadorans. From dishwashers to busboys, cooks and waiters, Salvadorans have become a conspicuous immigrant group in the workforce of metropolitan eating places--so much so that it is rare to pass by the flapping doors of a restaurant kitchen and not hear Spanish spoken above the din of pots and pans.

In more than one instance, restaurant owners have said it is a Salvadoran who douses the lights and locks up for the night.

"I think 30 to 40 percent of the kitchen staff in Washington is Salvadoran," said Giulio Santillo, owner of Terrazza in Alexandria.

"We all have them," adds Dominique Restaurant proprietor Dominique D'Ermo.

Salvadorans now make up 10 percent of the 10,000-member Hotel and Restaurant Employes Union Local 25.

This is one of the reasons the union recently challenged the State Department's refusal to give temporary residency rights to Salvadorans who came here without visas seeking political and economic refuge until the war in El Salvador ends.

Against all expectations in the legal community, U.S. District Court Judge Charles R. Richey ruled he would hear the union's arguments in court, thus allowing a rare judicial review of a State Department position.

Many Salvadorans choose restaurant work because "there are many people who speak English and Spanish in restaurants, and they can help," said Vasquez, 32, who has worked at Dominique for seven years.

Until recently, employers have rarely cared whether their employes were legally allowed to work in the United States. But that is likely to change under a major immigration reform bill before Congress that would penalize employers who knowingly hire illegal aliens.

Most restaurateurs approached were reluctant to answer questions about Salvadorans on their staffs. One owner said that he did "not want to discuss the matter" and hung up.

Many feared that mention of their restaurant in a newspaper would automatically bring a raid from Immigration and Naturalization Service officers to their kitchens--a visit that could paralyze their operations if many of their employes, or key ones, are undocumented workers.

But those proprietors who agreed to talk repeatedly said they hired Salvadorans because they come looking for work, are reliable and do the "grungy" jobs--at today's minimum wage of $3.80 and hour--that Americans are not willing to do: clean toilets, wash dishes, shuck clams and slice tomatoes.

"That's the kind of work that Americans born here do not want to do. Americans do not want to be the servant of anybody," said D'Ermo. "They don't want to scrub dishes, wash floors. Black and white and everybody else. They just won't do it. They do it for one to two weeks and quit. They don't call. They just leave and come back for their check. Restaurant work is the kind of work they have to start on the bottom. But I don't blame them."

Like other employers, D'Ermo praised the Salvadorans' reliability. "They are very good employes, extremely dependable . . . even in the snowstorm last February, they were on the steps ready to work," said D'Ermo, who, like many others, has helped his best Salvadoran workers get their labor certificates and thus legalize their status here.

"When one Salvadoran is sick, they send in a brother to cover, and when they leave, they send a replacement. It's like having a built-in employment agency. They're just right there," said the owner of a swank K Street NW eatery who declined to be identified.

"They generally start washing the dishes, the pots and pans," said D'Ermo. "They arrive here and most are illegal aliens as you know. They start to work and depending on their willingness to learn English and remain in the country and learn the profession, we promote them to several positions."

That was the route followed by Diaz, 26, Garcia, 40, and Vasquez, who are all now legal residents of the United States. Diaz said that when he came to work for Kojiro Inoue at Sushi-Ko on Wisconsin Avenue NW four years ago, he could not speak a word of English. In order to communicate during Inoue's cooking lessons that followed, "I was like a pantomime," Inoue said.

Diaz now has his "green card," expertise in Japanese cooking and commutes from his Maryland suburban home to work in his boss's old car. He says he would someday like to return to El Salvador.

Garcia began as a dishwasher at Le Jardin when he came here four years ago. He now makes $500 a week cooking at Terrazza. "Many times we have bad luck to be apprehended by immigration," said Garcia as he sat at a table in his boss' dining room.

"Many times many of us wish to stay here. We ask for political asylum. Sometimes it's conceded, other times it's not given," he said. "Taking into consideration the political circumstances, the situation in which we are in our country, to return many times means that people meet death . . . the situation in my country is very dolorosa."

The immigration reform bill now before Congress provides that an employer found guilty of knowingly hiring an illegal alien would get a warning on the first offense, with fines ranging from $1,000 to $3,000 and possibly a year in jail for subsequent offenses.

Proponents of the measure, which include the AFL-CIO, say it will help stem the flow of illegal aliens across U.S. borders by eliminating one of the incentives that draws people to this country--the chance of finding a job.

Restaurant owners dislike the proposal because "we don't believe the government should be forcing employers to make a determination as to whether someone is an illegal alien. That's their responsibility, not the employer's," said Ronald Sarasin, director of governmental relations at the National Restaurant Association.

The association and other employers' groups lobbied to relieve what they said would be a "record-keeping burden" imposed by the immigration bill's requirement that employers with more than 15 employes keep records of employes' drivers' licenses, passports, birth certificates, social security cards or work permits to show they are either U.S. citizens or residing here legally. An amendment altered this requirement so that it will only apply to employers after a first offense.

Hispanic groups also oppose the so-called "employer sanctions" provision because they say it will lead to harassment and discrimination against Spanish-speaking and Latin-looking job-seekers.

Virginia is one of the few states that already has a law providing for employer sanctions. Since it was put on the books in July 1977, there have been 574 complaints from the public about foreigners working illegally--mostly in construction and restaurant work.

But only seven have gone to court and only two employers have been convicted, according to Frank Moniz, spokesman for Virginia's Department of Labor and Industry.

The difficulty is in proving that an employer knowingly or willingly employed an illegal alien, said Moniz. In addition "a lot of these guys have fake social security cards, and fake drivers' licenses and fake green cards and some of the employers aren't that interested in checking out if they are genuine or not."

"It's a hell of a burden on the employer," said Paul Loukas, president of the 150-member Washington D.C. Restaurant and Beverage Association. "Do we ask for birth certificates? I'm not even sure that's legal."

Local INS officials say that their enforcement of employers' sanctions will target certain employers who have had a record of hiring illegal aliens. "Targeting is going to be a major accomplishment for us," said Steven Stephanadis, assistant district director for investigations in the Washington office. Officials and restaurant owners say they are not sure yet what impact the measure will have on local restaurants.

Washington's acting INS District Director Robert B. Neptune notes that the immigration bill also proposes an amnesty to illegal aliens who have lived here before a cutoff date that has not been determined. This means there would be "less necessity to hire the illegal alien because with legalization there will be a ready pool of legal aliens," Neptune said.

Others think they already know the impact: "It's going to be a disaster for this business, because you won't have anybody to work as a busboy or dishwasher. In Washington, forget it." said Jacqueline Rodier, owner of Jacqueline's.