Nobody likes a perfect character. Someone who is super good at everything and gets everything right is annoying.
Even the most suave secret agents of indestructible superheroes need to make mistakes in order to make the story interesting.
There are two parts to using wrongness in a story. There’s the actual mistake (which sometimes isn’t known to be a mistake at the time), and there’s the consequences of the mistake, usually forcing the character to deal with powerful feeling of guilt or regret.
- Soup. It’s relatively easy to make a big vat of it using veggies on the cusp of spoilage (or for resurrecting already-spoiled onions, carrots, etc). I recommend freezing single meal-sized portions in plastic bags/freezer bags. That way you don’t have to thaw out the whole lot, which will inevitably lead to waste. Many soups can be made with canned ingredients: tomato sauce, beans, corn, broth (I recommend buying the sort that comes in a box because easier storage and less heavy for those who might have arthritis, etc), peanut butter (for Thai curry type soups), coconut milk, and so on.
- Flour. Homemade tortillas are basically flour + water + salt, fried up in fat. They make a delicious snack or a good vehicle to stretch out your meats and veggies. Very inexpensive, and doesn’t spoil. If you live somewhere prone to critters, I do recommend keeping it in a plastic bag or container. Experiment by mixing cornmeal and flour, too.
- Spices. Strongly-flavoured ones like ginger, garlic, etc go a long way as far as bringing new life to otherwise dull foods. They are great for bringing variety to dishes like fried potatoes, etc. Same goes with condiments. Having soy sauce, oyster sauce, mustard, honey, etc on hand will allow you to make a lot of different foods even if you only have a few base ingredients.
- Canned/Boxed Milk Substitutes. Almond milk, soy milk, rice milk, hemp milk, etc are all sold in the dry-foods area and keep indefinitely, unlike cold dairy milk.
- Vegetables that keep for a long while are: carrots (even when they get soft, they are perfectly usable in soups and stir-frys), potatoes, onions, winter squash (butternut, spaghetti, etc).
- Canned biscuit dough is great and keeps for a very long time in the refrigerator (and lasts indefinitely in the freezer). Also, conventional wisdom holds that they are good at least 3-4 weeks after the expiration date. They’re great for just eating as biscuits, obviously, but you can also use them as dough for pies and pasties. Pigs in a blanket, etc.
- Oatmeal can easily be made savory or sweet. Buy the instant packs or the rolled kind or steel-cut, whichever you prefer. They are a great way to bulk up soups (similar to barley) or add texture too foods that are too soft. Obviously, it’s dry, so it keeps pretty much forever.
- Cornmeal is cheap and stores forever. You can make grits (porridge) out of it by stirring it with water and salt and pepper (and cheese, etc)…or for a more sweet take, add honey and cinnamon and cardamom. (This is basically what polenta is). Cornmeal + water + flour makes great hoecakes, which you can have savory or sweet, and bulk up meals when you cannot afford fresh ingredients.