On my initial visit to Cala – the first restaurant in the US by star chef Gabriela Cámara from Mexico City – it took 20 minutes for a waiter to take my order for a paloma cocktail (with grapefruit and tequila). Once it finally arrived, so did our sopes, and our ling cod salpicón, and our silky trout tostadas, and our sweet potato with bone marrow, and salsa negra. All at once. Albeit with a warm smile and a sincere apology.

But at this point last autumn, the airy, soaring, seafood-centric restaurant, high on sustainability credentials, was just a few weeks old, so I chalked the problem up to typical opening kinks.

Gay San Francisco: a guide to clubs, bars, drag shows and queer culture Read more

Turns out it was just that, plus the sort of hurdle never before faced by a buzzy, high-profile new restaurant: 60% of Cala’s staff have no prior restaurant experience and were trained from scratch. And 70% of them – all full-time employees – are former prisoners. The second time I ate at Cala, the service was as smooth as Cámara’s midnight-black beans ($4), a must-order side dish steeped in avocado leaves and pureed.

The radical hiring idea came from Cámara’s general manager, Emma Rosenbush, who once worked at the Prison Law Office across the bay in Berkeley. In a rapidly gentrifying city, where cooks and servers can no longer afford to live, Cala offers a radical solution to the industry’s hiring crisis. And, as if that weren’t enough to warrant a visit, the food is exceptional, and great fun, at a restaurant that has already become a classic.

• Dinner for two about $100 without drinksala, 149 Fell Street, +1 415 660 7701, calarestaurant.com