Soups

oo I've got plenty. Egg fried rice with fish fingers/fish sticks, chicken dipper wraps (w/ salad, onions and sauces) and bachelors pasta packs with added ham, mushrooms and cheese.

Boil some spaghetti. Add butter, and lots of salt and pepper. It’s surprisingly delicious.

Probably boiled egg. It's cheap and also doesn't require any cooking skills!

Oats with milk, in case I understood you right?

my jam used to be some spicy noodles (I make my own ramen these days but I would absolutely go buy a bunch of those 20 cents a pack dry ramen back in the day) anyway that and some frozen mixed vegetables and maybe a sliced egg and/or some chicken thigh meat, those tended to be cheapest , I used to call it Ghetto Pho

Instant noodles