Most supermarkets I know have sections where they have meat that's about too old to sell and thus gets marked down
Buying that way is great
Getting a roast for cheap can be cut down into smaller pieces, and probably cheaper than the equivalent weight of prepared stew meat chunks
Take about a pound of stew sized beef or whatever meat you have (chicken works fine too) and heat up a pot. Dump the meat in and let it brown, seasoned with whatever you got-I like paprika and chili powder best-, then pour in water just to cover and let simmer on relatively low heat for a couple of hours. During last hour or less of cooking, throw in rice, lentils, potato, or whatever fucking veggies you care for.
Potatoes, most veggies, and especially dry rice and lentils are cheap as hell. The meat should be reasonable if you look for deals, and spices are an investment but usually last a while.
Alternatively, buy tortillas and shredded cheese, fry small chunks of meat in a pan, then roll up the meat, cheese, and whatever else you care for and leave on the heat for a bit to crisp up the tortilla and melt the cheese
Hell, even for a good fucking dessert you just need a premade pie crust, a jar of molasses, cinnamon, sugar, and flour
3/4 a cup of molasses mixed with a cup of hot water and 1/4 to 1/2 a cup of flour and some lashes of cinnamon and a quarter cup of sugar
Pour that shit into the crust and sprinkle maybe another half cup of flour and cinnamon (maybe with some butter cut in) over the top. Only do this if you want something slightly more simple to cut the flavor of the molasses and bake at 350 F for 25+ minutes until the molasses mix has firmed up enough to stick in a utensil and have come out clean
Molasses pie is actually so goddamn easy I've almost become addicted to the shit