Brooks Headley departed from his top-of-the-food-chain gig as pastry chef at Del Posto in 2015 to channel his punk-musician origins into a solo project: a seditious, moshing, 270-square-foot Lower East Side restaurant that specializes in a remarkably gratifying vegetarian burger. The place is an ever-rarer reminder of individuality and tenacity in New York City. At its busiest moments, the crowd streams from the six-seat storefront out onto the sidewalk, a breadth of humanity sharing the moment as they consume meat-free sandwiches and spontaneous vegetable creations, straight from the farmers markets. Every menu item costs under $10. Headley doesn’t entirely abandon his previous title: He channels every ounce of his dessert genius into two transcendent gelato and ice cream flavors that change daily and come squashed together in a paper cup.