Need ideas!

I need ideas for my husbands lunch. He does HVAC so you never know where he’s at and typically doesn’t have access to a microwave.

As of now 2 times a week he eats a spinach salad with chicken, and whatever else I throw in there. Other days he eats tuna, salmon, or some sandwich (like pb&j). I’ve tried to cut back on deli meats with him since his doctor told him to.

He needs something filling since he burns a lot of calories with work. I want to switch it up for him, but need something non microwaveable. He’s not really a picky eater either.