Finding qualified chefs has been a challenge, much to Mr. Giusti’s frustration. While many chefs tell Mr. Giusti they support his mission, working in a cafeteria doesn’t have the same cachet as in a restaurant. “They don’t think about it as a real chef job,” he said.

Making all that marinara sauce and meatloaf on site requires skilled labor. Ingredients need to be cleaned, cut and cooked, rather than just reheated, so the staff has to be trained in food handling and safety and, to varying degrees, knife and cooking skills. The kitchens must also be converted to scratch operations , with the right equipment and space to prevent any chance of cross-contamination.

Most worrisome is the number of students eating the meals: just 53 percent for the first half of this school year at the Morrisania campus, down from 66 percent for the same time last year, even though every New York City public school student is eligible for a free breakfast and lunch each day.

Mr. Giusti, 34, is unsurprised by the numbers. Both he and school officials point out that lunchtime routines at the four Morrisania schools have been disrupted: Before this year, students ate only in classrooms. Now, everyone eats in the cafeteria.

Before he even reached the Bronx, Mr. Giusti knew there would be hurdles: He had already taken over all the cooking for the nine public schools in New London, Conn., where Brigaid is now in its third year.