Let me think.
breakfasts
I like to make a berry crumble, really simple, frozen berries, butter, oats, some sugar. You could probably make about 3 crumbles with a block of butter for that.
you could do pancakes, flour, milk, eggs
lunches
get a bag of dried broth mix, tinned tomato’s, some stock, and some bread. If you can, get some veg on offer to go in.
pizza, just flour and water base, tinned tomatoes, herbs, and some random
vegetables as toppings. When desperate, I have used breaded fish for meat instead of salami. Sounds weird but it was fine. You can put anything on it. Get a bag of potatos and tin foil, slice the potatos, rub oil on the potato slices, put them in tin foil, season, and bake.
omelettes
Dinners
a stew? I like to make a sausage stew, haven’t made it in a while. Tinned tomatos, leeks, stock, etc.
spaghetti bolognaise with lentils, beans and mince to stretch it. Sounds weird I know but it can be ok.
Hope that helps