Joey Allaham, owner and founder of the iconic kosher restaurant Prime Grill, has conceded that there are only two ways to cook a steak: broiled or grilled.

With fish, that’s not the case. Allaham’s latest food venture travels far beyond the world of beef to a yet-unexplored terrain: kosher Japanese cuisine. Last month, Prime Grill’s parent corporation, Prime Hospitality Group, purchased Butterfish, a traditional Japanese omakase restaurant that opened in the spring, and the restaurant’s new kosher iteration opened at the end of the month with certification from the Orthodox Union.

“I know meat, but I fell in love with fish,” said Allaham, who described buying the restaurant as a “dream for a restaurateur.”

Butterfish, Allaham said, is the first non-kosher restaurant he has purchased and turned kosher. While its management has changed, six traditionally trained Japanese chefs continue to run the restaurant’s kitchen.

Led by Chef Hitoshi, the Japanese chefs have not altered their cooking techniques since the switch. Allaham himself has accompanied the chefs on several fishing trips to ensure the freshest catch.

“We go fishing in Montauk together about once a month,” said Allaham. In their most recent trip, the focus was on tuna and striped bass, both in season.

“Fish is a much more delicate
art than meat, and it was essential that we maintain chefs who know the art,” said Allaham.

Aside from holding onto the existing kitchen staff, the hardest part of buying a pre-existing restaurant is maintaining old customers, said Allaham. “We have to make sure to cater to previous expectations, while forging even higher ones,” he said.

Thus far, the clientele is evenly split between kosher clients and non-kosher ones. The restaurant’s previous patrons continue to come, due in large part to their loyalty to the Japanese chefs. “If you’re not kosher, the only thing you’ll be missing is shrimp,” said Allaham.

Still, the entire menu had to be overhauled in order to accommodate the demands of kashrut. Though the restaurant’s original menu offered very “limited” options, the current menu has expanded to include nearly 10 entrees, not including the sushi bar. The menu features Yuzu Miso Cod, Wild Salmon Poelé and Grilled Bronzini in Sudachi Caper Sauce in addition to several chicken and meat options.

“Jews like a lot of options on the menu — they wouldn’t be happy selecting from just one or two choices,” said Allaham. “Even in the specific niche of Japanese cuisine, variety is important to our success.”

Expanding the palette for kosher clients is one of Allaham’s main goals. “Kosher doesn’t need to mean compromise,” he said. “I want to give kosher customers the same taste and experience they get in non-kosher restaurants.”

But the new move has its risks.

“Few ventures in the past have focused so heavily on fish,” said Elan Kornblum, publisher of Great Kosher Restaurants Magazine. He noted the city’s kosher fish restaurant, Turquoise, which had a branch in Manhattan that has recently closed (a Queens branch is still open). “Fish first is a risky experiment in the kosher world,” he said.

Of his many trademark kosher eateries, Butterfish is the one Allaham wants to take on the road. He mentioned Teaneck, N.J., as a possible location.

“This is something different, something new, something fresh,” he said. “This is not just hamburgers, and it’s not just fries. Butterfish will bring a new food experience to kosher observers.”