baked potatos stuffed with tuna and cream cheese. Top with some cheddar and reheat in oven few minutes before you want to eat.
Other types of soup? I do butternut soups in a variety of forms, also spinach is popular chez Bling. All are appropriately smooth if that's important (I wouldn't eat soup with "bits" in it until I was about 29 so I have some sympathy with your DC).
Will they eat curry? Or is that in the category of wet food mixed up with other things?
Meat based pasta sauces - eg spaghetti bolognaise will in fact benefit from being left for a while. Onion, bacon with tomatoe is nice too and can be done in advance and reheated and you just have to cook the pasta. Also sausage pasta which is a standby in our house - fry sausage meat (out of the cases) in a little oil with some fennel seeds, garlic, chilli and lemon zest. Add a generous splash of wine and equal amounts of milk, allow to bubble for a few minutes then stir in some creme fraiche. You could easily leave that somewhere then just heat it through when you cook the pasta later.
Also, there are things you can make but then just "cook" very quickly when you need them - eg fresh burger patties can be premade and kept in fridge until you're ready to fry them. Ditto grilled chicken and salad just needs the chicken marinating in the fridge until you stick it under the grill for 20 minutes when you want to eat.