There’s a problem with school lunch in America. Big Food companies have largely replaced the nation’s school cooks by supplying cafeterias with cheap, precooked hamburger patties and chicken nuggets chock-full of industrial fillers. Yet it’s no secret that meals cooked from scratch with nutritious, locally sourced ingredients are better for children, workers, and the environment. So why not empower “lunch ladies” to do more than just unbox and...