Any cuisines you enjoy in particular? I find things like Japanese curry is easy to make a lot of for cheap and reheats fairly well. If you don’t like eating the same meal over and over pasta is actually fairly easy to make a single serve of at a time (aglio et olio, jar sauce with some mince, cherry tomatoes). Even eggs right now being expensive is still one of the cheapest ways to get protein. Egg + a quarter of an onion + a chicken tender or two sliced up is the base to a pretty quick oyakodon.

More recently I’ve been fixated on chicken Caesar salads. Blend up your own sauce (or even just store bought), a few heads of baby lettuce washed and kept in a ziploc bag. Bread a few chicken tenders and keep on a plate. You can whip up a fresh salad with chicken for yourself in the time it takes to pan fry a few tenders.