Well, given a recipe as a base, I've cooked enough in my life to know how a dish will change if I add x spice, or reduce the amount of y ingredient, or cook it for just a bit longer or shorter. From memory, I cannot cook very many meals, though I know enough to both sustain myself and give a bit of variety. Anything involving pasta is very easy, as are most meats. Eggs are straightforward and fast. Toast and bread work wonders for bases and sides. If preparing things that do not require cooking is under the same category, then I can use basically anything I have available.