If you’re wondering about how and why food gets appropriated—i.e. when Americans consider it their own—think about this: Eating Italian food was once considered “slumming.” So what does it take for a foreign cuisine to melt into America’s pot? We talked to Krishnendu Ray, the director of NYU’s Food Studies program and author of The Ethnic Restaurateur, a book about how immigrants to the U.S. shape the food culture, who gave us a step-by-step breakdown of how a cuisine can go from unnoticed to avant-garde; from popular to prestigious.

In the late 19th century, says Ray, most restaurant food of note in the U.S. was Germanic: spaetzle, sausages, and often served in beer halls. But as a wave