Public school teacher here. Good luck on your quest, seriously. I'm afraid you're up against a juggernaut here. When I questioned my administration about our junky lunches, I received the following (paraphrased) answer: We have a responsibility to feed kids. Our lunches meet state guidelines. And this is the food that kids will eat.

But like others have said, this food is often thrown away. Or the kids, if allowed to choose, won't take the cooked vegetables. They'll opt for a banana or orange instead, which often goes uneaten. On Taco Tuesdays, when walking tacos are served, they'll often choose the bag of Doritos and ask for the cheese sauce poured inside. No meat. No corn. It's disgusting. When I asked my administrator about THAT particular lunch choice, he merely stated that the cheese sauce has the requisite protein, so it counted as the entree. Pretty sad, I told him. He rebuffed that comment by stating there was no other choice, there was no money to hire staff to cook any kind of lunch, and he wasn't going to ask the current staff to do more because they might quit.