Deep in the blue-collar San Diego neighborhood of Kearny Mesa, wedged between auto dealerships and neon-lit fast-food chains, the chef John Hong is performing nightly timed shows of the Japanese ritual omakase.

This isn’t a theater. It’s the restaurant Hidden Fish, a Lilliputian space of only 13 seats wrapped around an L-shaped bar. But you could be forgiven for thinking you’re watching a kind of choreographed dance. Diners, divided into 50- and 90-minute zones, gather and eat for a set time before new customers are rotated in. In the center, wielding his knife like a conductor’s baton, stands Mr. Hong, doling out precise, timed portions of exquisite nigiri sourced from across the globe.

Omakase, which translates to “I’ll leave it up to you,” is a tradition of Japanese dining in which a chef creates an (often elaborate) tasting menu, and customers eat whatever they are served. Mr. Hong first encountered the concept of timed omakase during a visit to New York’s Sushi by Bou last year. He says he was inspired by how that restaurant, which serves meals in tight 30-minute increments, slashed price tags and made omakase accessible for almost anyone by putting diners on a clock.

Mr. Hong, who grew up in Los Angeles and trained under sushi master Yukio Sakai, decided the concept was worth gambling on in San Diego. He opened Hidden Fish in September, offering 30-minute and 90-minute meals, and very quickly had to make an adjustment.