In The World on a Plate: A Tour Through the History of America’s Ethnic Cuisine, Joel Denker tells the story of one Jeno Francesco Paulucci, who saw in the lowly bean sprout a previously untapped resource for restaurants desperate for fresh vegetables as a result of wartime rationing. Paulucci was the man who, starting in a pea plant in Iron River, Minn., brought us the Chun King product line. And while the immigrant with entrepreneurial vision is an oft-told tale, even Jeno himself knew there was something peculiarly American about an Italian immigrants’ son who rose to riches selling Chinese food in a Scandinavian region.

In such loopy cross-pollinations are contained not merely the culinary history but also the ethnic, social, and cultural history of postwar America, suggests Denker, a lecturer in the history department at George Washington University—and a writer whose own history is itself a rich weave of influence and association.

The son of a Jewish father and a New England Protestant mother, Denker taught for a year in Tanzania upon graduating from college, returning to the States to found an experimental high school in the District. (It became the basis for his first book, No Particular Place to Go: The Making of a Free High School, published 30 years ago.) His career in more traditional education would eventually take him from New York to San Francisco and back again to D.C., where he’s lived for the past 25 years.

It was in New York that Denker became a serious eater, carrying his heavily thumbed copy of The Underground Gourmet as he explored the city by way of its restaurants. “Chinese, Japanese, Thai, Vietnamese, Indian, Bolivian, Dominican, Ukrainian…everything. You name it.” In San Francisco, he found a Bay Area version of that same guide and acquainted himself with the joys of Peruvian and Nicaraguan cooking.

By the time Denker returned to the D.C. area, his professional and private passions had begun to mingle. Food had become another angle, another point of entry, from which to explore the social history that had always fascinated him. Hoping to contribute a guidebook like the one that had inspired him, he produced Capital Flavors: Exploring Washington’s Ethnic Restaurants in 1989.

His latest book, seven years in the making, grew out of columns he began writing in the early ’90s for the InTowner newspaper about the city’s ethnic folkways. A New York agent sniffed at an early version of the manuscript—”Everyone knows this stuff already”—but Denker was undeterred. The making-of-Progresso story might not be churning narrative drama, but then it’s not a story in the conventional sense; it’s a pattern, an American archetype. The evolution of that company and others like it, Denker discovered, mirrored the evolution of European immigrants in the 20th century: Scruffy mom-and-pop establishment embraces the mainstream, assimilates, asserts its reinvented identity, and casts off the last remaining vestiges of “ethnic.” The challenge was finding those stories.

One day, flipping through a copy of New York Places and Pleasures, one of many books in his extensive collection, Denker came across the name of Abraham Sahadi, founder of the Sahadi Middle Eastern food empire. In the pursuit of personalities and stories for his book, he tracked down Bob Colombosian, scion of the Colombo yogurt family, in Salem, Mass. (The company was sold to a French conglomerate in 1977.) His Guide to Ethnic New Orleans led him to the Uddo family, which originated the Italian product line that became Progresso.

“It was,” Denker says, between bites of an Indian buffet lunch, “a lot of detective work. A lot of serendipity.”

His current culinary obsession? Cloves. He’s already produced three columns on the subject for the InTowner. He’s been spending hours in the library, boning up on 16th-century botanical theory.

Is there a book in that, too? The Clove: A Short History? Denker won’t say.

“I’ve learned to let it percolate,” he says, smiling. “Just let it organize itself.” —Todd Kliman