I agree no lasagna. And yes! to the throwaway foil pans.
I've made a number of things over the years.
Chicken rice & mushroom casserole - there is no condensed soup in my recipe, it's easy and reheats well if there are leftovers. I received this dish after my youngest was born and it's been a family favorite ever since. My picky eater just avoids the mushrooms.
Crock pot French dips, I take over sliced meat, a container of the au jusand a package of crusty buns along with a veggie pasta salad.
In the winter, I make a lot of homemade soups, a large container with a loaf of warm homemade bread (use bread machine) is always a hit.
Cheddar chicken pot pie - heavy, rich, but so good.
I almost always add fresh fruit cut up to any meal I give. And a homemade dessert.
Funny story, I took a meal to a friend going thru chemo. As an extra, I also brought a quart of homemade spaghetti sauce I'd made the day before in case she needed a quick meal for her kids since her husband traveled overnight frequently. She pulled it out of the fridge a few days later and warmed up a bowl thinking it was soup. Halfway thru the bowl she figured out it was sauce. Moral of the story, label everything, and include any cooking/reheating instructions.