WASHINGTON - The only thing standing between executive chef Richard Tassiello and his fresh tarragon was a determined rabbi and 3,000 years of Jewish food law.

In the middle of a recent lunch-hour frenzy at the new Pomegranate Bistro, Tassiello - wearing a crucifix - cast a pleading look at Rabbi Joseph Pinto - wearing a yarmulke - and held up a bundle of herbs.

“Can you do these right away?” Tassiello asked.

Pinto grabbed the greens and hurried to a tub filled with water, salt and vinegar. Because the Torah forbids observant Jews to consume insects, even accidentally, fresh produce in a kosher kitchen isn't so much washed as prepped for surgery. Pinto vigorously sluiced the herbs, rinsed them and dunked them in the tub.

“The salt and vinegar makes the bugs come free,” Pinto murmured as he scrutinized each stem under bright fluorescent lights. “Ah, ha,” he cried, pointing to a nearly microscopic mite swimming for its life.

Pinto is a kosher supervisor, or mashgiach, for the Rabbinical Council of Greater Washington. Recruited, trained and assigned by the council, he is posted full time at the Pomegranate Bistro in suburban Potomac, Md., which opened this week as the region's newest fully certified kosher restaurant.

Pinto and about 30 other in-house inspectors serve as a little-seen kosher police force in restaurants certified by the rabbinical council. They ensure that dairy never touches meat, that a knife used to bone fish is never used to cut steak, that no creepy-crawlies ever make it into a salad. They turn on the ovens in the morning and burners as needed (to fulfill the edict that a Jew be involved in the cooking), and they search every label for the telltale circled “K” or other marks of rabbinical correctness.

And when they spot a slip-up, they can trash the food, shut down the line and order any offending pot or pan, unto an entire oven, to be cleaned and re-sanctified before it goes back in service.

“It happens once in a while,” said Pinto, a French immigrant who has been a kosher supervisor in restaurants for the past five years. “In a busy kitchen, people can a make a mistake. Most of the time, they are very nice when we have to stop something.”

The supervisors, who often stay for years at a given location, maintain remarkable vigilance over their restaurants, typically being the first to arrive and not leaving until after the last dish is washed. (Indeed, Pinto literally holds the keys to the bistro kitchen; neither the owners nor managers have a set). Sometimes, the supervisors will take on other, non-kosher duties, such as managing inventory or clearing the cash register each night.

“These restaurants contract with us to guarantee that they maintain kosher status, and they quickly learn that the supervisor is worthy of the highest trust,” said Rabbi Binyamin Sanders, who runs the program for the rabbinical council. “It's a relationship that works for everybody.”

The Washington area has more than 30 certified kosher restaurants, bakeries, caterers and other outlets. Any outlet that serves meat is assigned a full-time mashgiach.

“It's growing all the time,” Sanders said. “Now there is a guy who wants to open a Chinese place.”

The certification process for each new restaurant begins weeks before the first customer is served. Sanders and his team of rabbis descended last month on the building, a former Chicken Out, being converted into the Pomegranate Bistro. Much of the equipment was new, but anything that ever had been used or even tested with real food had to be kosherized.

“If we find so much as a crumb, we kosherize it,” said Sanders on that day, wearing yellow rubber gloves with his shirt and tie. “Toasters are the hardest.”

Most kosher cleaning has to do with applying extreme heat. To kosherize the industrial dishwasher, they upped the water temperature for a few cycles, from 190 degrees to 212 degrees.

They lined the warming ovens with Sterno burners to boost its maximum temperature for two hours. As Sanders heated the iron cooking grates to a red-hot glow, his assistant poured pitcher after pitcher of boiling water over twin steel prep tables.

There are two of almost everything in the bistro kitchen: twin stacks of ovens, twin deep fryers, a brace of Southbend six-burner ranges. One for fish, the other meat. Not all Jewish cooks are familiar with the Talmudic separation of fish and meat, but it is an Orthodox tenet enforced by the local rabbinical council.

“There is no surf and turf in a kosher restaurant,” Sanders said. Cooking utensils are coded by the color of their plastic handles, red for meat, blue for fish and green for parve, or neutral, foods such as vegetables and pasta. In the old days, kosher cooks had to mark their equipment with dabs of paint or metal stamps. Most health regulations now require separate color-coded utensils for meat, raw meat and produce, bringing all commercial kitchens closer to the kosher system.

“They're catching up,” said Rabbi Gedalia Walls, one of Sanders' kosherizing crew, of the cooking practices in the non-orthodox world. “Now all they have to do is learn not to put meat and cheese together.”

Before any of the knives, spoons or whisks can be used, Pinto takes the whole lot to a nearby synagogue and dips them one by one in a mikva, a ritual basin filled with collected rainwater.

Nothing at first glance would suggest that the Pomegranate Bistro is a scrupulously religious eatery. The dark wood decor is generically upscale, and the wasabi tuna, chicken Florentine and beef satay could be found on many a modern American menu.

But diners won't find shellfish among the offerings, or rabbit, pork or any other food forbidden by kashrut, the Hebrew term for keeping kosher. There is not a milk product on the menu, or even in the building.

“It's easier just to keep dairy out of the restaurant altogether,” said general manager Eli Verschleisser, a former kosher inspector. “We won't allow any outside food in at all.”

Verschleisser is Jewish, as is assistant manager Martin Chavez, but Tassiello is Catholic and most of the kitchen workers are Latino.

“I'm not Jewish, but this tradition is very old and I appreciate that,” worker Delfino Lopez said. “We are very careful to do it right.”