Healthy school lunches

For a picky eater? My son is starting Kindergarten and I know he’s way too picky to eat anything the school would serve. So I plan on packing his lunches for him, but I’m so lost on what to pack. Everywhere I’ve looked has given unrealistic ideas for kids who are super picky, but I also kind of want him to adventure out and eat more of a variety. So here’s what I have so far that I know he will eat:

Main:

*Almond butter on wheat sandwich

*Chicken nuggets in thermos

*Cheese quesadilla

Snacks and sides:

*Apple Sauce

*Pretzels

*Crackers

*Granola Bar

*Yogurt

*Banana or apple slices

*String cheese

Drinks:

*water

*juicebox

*tea

I feel like this is not enough variety, and I also feel like it’s not enough to keep him full throughout the day. I plan on packing a treat each day too, wether that be a rice crispie treat or cookies or whatever, I’m not sure. But I really wanna try to keep things as healthy and filling as possible. Thanks in advance!