One recent Saturday afternoon at Tache Artisan Chocolate, a newish store on Broome Street, a tall, magnetic-looking man named Sean John made his way to the counter of the crowded shop. Mr. John, 38, was a regular; he owns Spur Tree, a Jamaican bar and restaurant around the corner. Before he could order his usual coffee (Ethiopian blend), the owner of Tache, Aditi Malhotra, thrust a tray in front of him. It was a new concoction she was working on: dark chocolate truffles flavored with fennel and mango. “Tell me what you think,” she said.

Mr. John’s taste buds were apparently still asleep. The crowd at his restaurant had not left until 4 in the morning, so it had been a long night for Mr. John, who also lives on the Lower East Side. “It’s good, a little spicy,” he said in a light Jamaican accent, “but you know, I think I’ve got to try it again when I’m not so beat.” Ms. Malhotra took it in stride, partly because she knows how partial he is to her dark-chocolate truffle with sea salt.

Amid the rapidly disappearing grit of the Lower East Side — the dive bars, the homegrown boutiques and a handful of derelict storefronts — sits Tache, a most genteel chocolatier where bonbons and truffles cost $2.50 apiece. But the Broome Street store is more than just an unusual spot on an unlikely block — it has become a gathering place for the neighborhood’s diverse characters.