The city’s publicly owned grocery stores will offer a 30 percent discount on basics, Mayor Zohran Mamdani announced on Monday. One of his key campaign promises to tackle affordability, the mayor plans to establish five city-run food stores, one in every borough, as a way to bring down food costs, the first model of its kind in the United States. A collection of essentials, including all fresh produce, meat, and seafood, will be priced 30 percent below typical retail prices. Other basics like cheese, milk, and bread will be 20 percent off, with other products priced at market rate.