But when he thought about that possibility, he says, “I was excited.” And he has been pleased with the mix of customers at Basil so far. Often, he says, he will survey the dining room, study the clothing and grooming of customers and try to make educated guesses about them: Jewish or not? Hasidic or just Orthodox? From Crown Heights or Flatbush or Manhattan or even New Jersey? At any other kosher restaurant in the neighborhood, there would be no chance for speculation — and nothing like the crowd on a Tuesday night when he and I looked out and analyzed the room together.

In addition to the Hasidim at many tables, there was a blond, tan woman in a low-cut, sleeveless summer dress sitting alone at a table for two against one of the glass walls. She seemed to be in her early 50s, and she slowly sipped a glass of red wine. At a table for four near the back of the room sat four younger women, only one of whom wore a top with sleeves that covered her elbows. And at the table beside theirs: two Hasidic men and two black men. It turned out they were in Brooklyn politics, and that one of the Hasidic men had chosen Basil as a rare kosher place with an atmosphere and attitude that would feel familiar and comfortable to their non-Jewish colleagues.

I later called one of those colleagues, Ron Thomas, to ask him what he had made of the place. Thomas lives in downtown Manhattan but sometimes works in Crown Heights for Representative Yvette Clark, a Democrat whose district includes the neighborhood. He said he was “captivated that a place like this could exist in Brooklyn, on that corner” and vowed to go back, possibly with his fiancée — among the many ways Basil impressed him was that it struck him as romantic.

“I think this is something that could be groundbreaking,” he said. “I was really taken aback: Wow, where has this place been? It’s a long time coming.”

HE’S JUST ONE OF many people I encountered, during my mornings, afternoons and evenings at Basil, who see it as a potent symbol, whether positive or negative or something in between. “I think it will be very iconic in terms of the future of Brooklyn,” says the Rev. Caleb Buchanan, a priest at a Roman Catholic church just a few blocks from the restaurant. Father Buchanan, who is black, is a lifelong resident of Crown Heights.

He first visited the restaurant in March — on Palm Sunday, in fact — and was moved by the solicitousness of Perez and her staff, who sometimes rush out to introduce themselves to people looking inquisitively at the restaurant, especially if they aren’t a kosher establishment’s most likely customers. He now drops in at least once a week, and says that if, before Palm Sunday, “you had told me that I’d be spending time visiting and supporting a kosher restaurant in the neighborhood, I wouldn’t have believed it.”

That’s true as well for Joanna White-Oldham, whose work with a Brooklyn organization called the Center for Active Learning takes her frequently though Crown Heights. In July, a Jewish colleague invited her to Basil for a business lunch, and she noticed, with great joy, that she wasn’t the only black customer among the Hasidim. It occurred to her that over the many years she had lived in Brooklyn, she had seldom, if ever, seen a picture quite like this, and she liked it. So she kept coming back. For a family meal to celebrate her 10-year-old daughter’s recent baptism, she didn’t choose a restaurant in nearby Bedford-Stuyvesant, where she lives. She chose Basil.