Luis Reina was preparing dinner for a crowd: turkey stew, rice and cucumber salad. The recipes were simple — chop the vegetables, brown the meat — but the process was anything but straightforward.

Each box of ingredients had to be searched for contraband. The knife was tethered to the counter by a sturdy chain, and the metal spoons came from a cabinet flanked by security guards. The sharp-edged lids from tomato cans had to be tossed into a trash can inside a locked cage. Several kitchen assistants were clad in jumpsuits and carefully patted down before they could start work on the meal — for 3,800 people.

Mr. Reina, 56, is a cook on Rikers Island, New York City’s notorious 415-acre jail complex in Queens. He commutes two hours from Flatbush, Brooklyn, to prepare meals for the jail population and staff alongside roughly 50 other cooks in the larger of two kitchens on the island.

He says he’s frustrated by the poor quality of the meals, in which every ingredient and recipe is dictated by the Mayor’s Office of Food Policy. Most vegetables and fruit arrive at the jail canned or frozen. Salt is off the table, banned since 2014 for health reasons.