I buy foil trays with lids, really cheap in the right places, £1 for 7 big enough for lasagne or cottage pie for four, £2 for four that take a whole chicken, spatchcocked (is that even a word) with par boiled new potatoes, cherry tomatoes, garlic, basil, butterbeans, carrots and stock.
I just defrost in the fridge and bung it in the oven. I am a big freezer cook atm and am doubling everything I cook quantity wise.
My particular favourite is a casserole I made up. 2 ½ lb Beef (shin or skirt) in seasoned flour pan fried, chopped onion, shallots, carrots, two turnips, a cup full of soaked dried wild mushrooms plus soaking liquid, beef stock cube, bottle of bitter, thyme and rosemary. Cook it for four/five hours on low .... not in a slow cooker it doesn't taste the same to me. Freeze half in a foil tin with a lid and then stick it in the oven with cheese dumplings on top, frozen peas = meal without effort.
I have got a new 7ft tall freezer
, I have filled half of it in less than a month of double cooking meals.
I reuse the trays where I can - the one I used tonight is on its third meal.