Shelflife has always been a big hurdle to cooking for me, and I’m a bachelor.
The rest of the meal comes from things that will happily sit for weeks on end in the cupboard without going off. Things like: Pasta, onions, tomato pureé, garlic, stock cubes, kidney beans, lentils, rice, bacon, etc.
This does mean that often the one fresh thing I use is the meat in any given dish.
This is analogous to how people used to cook as well, keeping a large store of long-life ingredients and merely supplimenting them with whatever was fresh.