I've been packing my kids' lunches in these bento boxes since they were 18 months old.
They are called Laptop Lunches. Ever since they could safely stand on a stool next to me at the kitchen counter they've "helped" me make their lunches and have had say within reason regarding what goes in them. Since they've been doing that for so long they started making their own lunches at a pretty early age. DS8 makes his own lunch without any interference from me unless he needs help getting something off a high shelf or opening a stubborn jar. I really like these boxes because it's made it easy for my kids to make themselves healthy lunches for so many years. Last night DS8 packed an almond butter and banana sandwich, string cheese, applesauce, and a Clementine. I didn't choose any of it. They've put everything from sushi to ants on a log (celery smeared with almond butter with raisins on top) in them. The sets are dishwasher safe and microwaveable. If they lose the boxes inside I can buy new ones online.
The school cafe serves amazing, healthy food but it's expensive so I only left him buy once a week. The cafe has a salad bar and a fresh fruit bar plus a sandwich station and a pasta station. There's also different hot lunch available every day and ice cream or dairy-free popsicle available every Friday. The only drink options are milk, water or fruit infused water. One of the school's families has a local popular restaurant and they took over the school cafe contract when their son started Kindergarten. The food is of the same quality as the food at their restaurant and is made fresh. A lot of parents check out the monthly menu and will eat with their kids on the days that an appealing hot lunch item is served. I watch for their lasagna. It's incredible.
DS12 has moved on to other options. His current school has microwaves and fridges available to students. He quite often takes leftovers that he can heat up in the microwave along with fruit. The school is too small for a cafeteria but on certain days they will have food delivered from local restaurants for the kids who order it.