Kaz if I reckon there are 4 portions of eg casserole, I ladle it all out at once - one ladle on each plate, 2 in the freezable tub, in turns
I allow 'about' 100g raw meat per person but actually reckon on 1lb which is 454g (think of a quarterpounder - that's enough). Obviously if a pack of meat is 500g then I'd probably still do 4 portions.
The beef casserole we had tonight was done like that, but I do adapt a bit. This time, first time round we'd had most of the shallots and all the mushrooms (deliberately, but I'm used to it, it meant there was still half the meat). I stuck a note in saying 'add veg'. So tonight I quickly stir-fried a few mushrooms, a sliced red onion and some red pepper since I had it, and added that mix once the casserole had started bubbling (in the microwave).
The meat and sauce are what you need, so it's always easy, chuck in a few mushrooms (they can just go in as it heats), or tomatoes if you've got them waiting to be used up, etc.
Btw an old Mary recipe I have adds a teaspoon of ground ginger to the flour mix to toss in the bag, it's yum, I can dig it out if you like