Flavor does not matter, presentation does not matter but the food shouldn’t make you sick, and should ideally have enough calories per day for the average person to survive (2000 kcal min).
Edit: I am not in any danger of starving or malnutrition, nor am I insolvent. I’m mainly asking this question out of curiosity on how people would approach a solution :)
Beans, I love black bean burgers or pinto beans as a side. You can little bags of them from dollar tree but I think a bigger bag is a better deal. 3 bean salad. As for meats or fish, use your store apps to clip digital coupons, never buy meat that’s not on sale. That $40 roast will go on sale for 10.
Actually buy a small chest freezer. I usually buy proteins on sale and portion them out into the freezer.
Casseroles are cheap and filling. Buy two cans of green beans and a mushroom soup, fried onions.
Homemade granola is pretty simple.
Instant pot soup recipes are quick and cheap. I love beet soup, cabbage soup, chicken soup (from a whole chicken)
The pre seasoned meats from Aldi are usually a good price.
After Thanksgiving giving I usually purchase two turkeys, really cheap, they just want them out of the stores .
If you want lowest possible cost then canned stuff is out. Buy beans and rice in 20 lb bags. Hard to beat that!
For anyone lucky enough to have a WinCo foods in their area, they’re the cheapest I’ve been able to find for bulk dry goods. You can order 20-50 pound sacks of grains, beans, flour, etc., with a pretty decent discount on top of already low prices.