There’s a certain unspoken culture here, where the elite of kosher New York gathers, in a space which is perfectly designed for what half of fine kosher cuisine is about: not only the food, and not only the ambience, but also the people-watching.

“I like this new space because it’s built to people-watch,” Steve Traube, COO of the Prime Hospitality Group, laughs and gestures to the double-tiered-dining room.

An instant scan of the chandelier-lit room proves Jewish New York to be quite the shtetl, and observing others to be quite the delicious indulgence. Hedge fund managers sit with their wives — women in long-coiffed wigs, in fitted sleeved dresses and stilt-like heels — and watch each new guest make an entrance: check the gentleman’s yarmulke, or the young woman’s knees and elbows, for religious affiliation. Examine the lady’s ring finger and head, to confirm class and marital status (beware: hair that isn't a wig will always, somehow, look unfinished). In the far left corner, there’s a late-night business dinner; on the higher level of the hall, there’s the occasional politician, the shidduch date, the family outing, the boys’ club sports-watching events (private booths with televisions are available).

And it’s a shtetl with its own social diary: Who was that? Ah yes, the woman you met once at a dinner at the Pierre, with a reputation for knowing every charity board member ever; at the next table, the rabbi whose progressive lectures have been banned in certain synagogues and are now held in private homes instead. You pass by the parents of the last boy you dated, his mother sees you and indiscreetly elbows her husband, who subsequently spills his Johnnie Walker; there’s the guy you met once on the Upper West Side who talks about his exciting new life in advertising but whose English, his slight hints of Talmudic inflection, betrays a past yeshiva life. And the conversation subjects — community politics, the terrible state of religious-secular relations in Israel, foundation dinners, wedding gossip — there’s a steady tempo ostinato here. Or as we say, in our frumspeak: “There’s plenty of hock going around.”

“It’s very much a New York institution,” executive chef David Kolotkin says as he sits down with me over a platter of salmon tartar ($22). “The Frank Sinatra playing, the elegance, but also the comfort level — it’s cool here, but not too cool.”

This summer, Prime Grill, formerly on W 49th St, has moved to a new and more central location on W 56th Street, off Fifth Avenue. The space is larger than the previous one (now with occupancy for 360), featuring a bar in the center of the dining hall and a Herzog wine room for special events. Even the menu has expanded: “We now have a flatbread brick oven,” the manager adds proudly. “Cheeseless pizza: we’re working on perfecting it” — non-dairy, of course, because the OK-certified glatt kosher restaurant serves meat.

Prime Grill is a branch of the Prime Hospitality Group, a restaurant group renowned for its luxury kosher dining experiences, and one which has no need to place a single advertisement. Other locations include the Japanese steakhouse Prime Ko, Prime Solo and Pizza da Solo (dairy, Italian-inspired), Prime at the Bentley Hotel, and BB Prime (butcher and bakery) — not to mention an upcoming Prime Experience “Passover program” at the St. Regis in Laguna Beach (this subject for another time perhaps — the culture of American luxury Passover programs deserves an essay of its own).

“Everything’s by word of mouth here,” Traube says matter-of-factly. “The Jewish community, it’s really very small. Once some people know, everyone knows.”

The majority of the restaurants’ revenue comes from business lunches and late night dinners with partners and clients — patrons who know the manager by name and whom the maitre-d’ greets with a hearty slap on the back. “Our guests feel at home here,” Traube says. “They often have set places when they first walk in. Sometimes they call in advance and tell us, ‘I’m bringing important clients, take good care of this’. So it becomes a relationship.”

Notably: almost half of the restaurant’s clientele are non-kosher diners; the menu’s reputation precedes its kosher certification. “This is fine dining that just happens to be kosher,” Traube repeats several times — a philosophy which had first led Damascus-born butcher Joey Allaham to start the Prime Group, in 2000.

And indeed, the menu itself, aside from the sociocultural experience, will certainly impress the taste buds. With a reputation for the best meat in town, the restaurant employs seven full-time butchers, and its kitchen includes four walk-in refrigerators.

Rest assured that any dish will delight, but here are a sampling of recommended dishes that will certainly lure one away from any flirtations with vegetarianism: To start, try one of the specialty sushi rolls, the Katsumaki ($23), and the crispy rice with spicy tuna ($21) — a recipe which Chef Kolotkin tells me non-kosher restaurants have since copied. The crackling duck salad ($23) and the sliced prime filet on garlic toast ($26), a carnivorous take on bruschetta, make an appetizing lead into the meat course. The grilled wagyu angus ribs ($32), served alongside a lemongrass-ginger-soy marinade, are simply mouth-watering, while the Park Avenue rib eye 21 oz ($68) is a house classic. Prime Grill’s wine selection is diverse, mostly of the California, Israeli and French variety (my personal pick here is the Herzog Alexander Valley Cabernet Reserve). As for dessert, you’ll barely notice that the decadent tiramisu ($12) is non-dairy. Or else, opt for the pomegranate sorbet: it’ll be a refreshing finale before you exit the restaurant, stage right please.