I had lunch with my favorite 6-year-old last week. School lunch hasn't changed much since I was eating them. The cafeteria works pretty much the same too.
Our deal for the past few weeks is this: get good behavior reports Monday-Thursday of each week, and you can eat in the cafeteria on Friday. So far, this deal is working out well for me: I can feel good about what he's eating most of the time (because I'm packing it) and I'm getting good behavior reports. On Friday, he eats whatever he wants in the cafeteria, and I take a day off from packing lunches.
Last Friday, his lunch consisted of pizza, applesauce and chocolate milk. They offered him lima beans, but he passed.