I know these can’t be frozen but I like a nice stir fry. Bung into the wok whatever veggies or meat you have and cook with either rice or noodles.
Sausage casserole: Fry decent quality sausages, cover with a tin of chopped tomatoes, dried herbs (garlic if they like it). Meanwhile cook some spuds, mash them and stick the sausages with the tomato sauce into an oven proof dish, top with the mash and plenty of cheese, cook in the oven until cheese is golden brown.
We always played a game with veg soup when my nephew was little. He had to guess all the types of veg he was eating (I always cut them up into large pieces), anything up to 8 types. It was the only way I could get him to eat it.
I also make easy barbecue sauce with chicken, onions and garlic, which all goes into the oven for a quick meal. Can be eaten with rice (that I hide veg in) or pasta.