Most of my recipes are built on some staples that I always keep on hand. The foundation ingredients that I can't cook without. None of them are exotic, and chances are if you've got here, you have them, or their equivalent anyhow.
Flour: whatever kind you like, really. Personally I use 1/2 whole wheat and 1/2 all purpose.
Corn Meal: another one of my favorite "nutritious and versatile" items
Milk: again, whatever you like. Ricemilk, Soymilk, Almond Milk, Cow Milk, Goat Milk. tend to keep regular whole milk in the house for coffee (COFFEE!!) and tea, and a big box of powdered milk for cooking and baking.
Eggs: Or your favorite egg replacer. About.com has a pretty good article on egg replacers.
Onions: Tasty, versatile, nutritious onions.
Carrots: Also tasty, also nutritious, also very versatile.
Garlic: In cloves, in jars or just powder, garlic can liven up almost anything!
Rice: Any kind. But real rice, not instant, minute, or boil-in-the-bag.
Noodles/Pasta/Macaroni: Whatever you call them, they can complement, round out or stretch a meal with ease.
Butter: Or margarine, as long as it's the stuff you can cook with. I say that because some of the new fancy shmancy "buttery spread" type stuff says right on it "not recommended for cooking or baking". Believe them.
Baking Powder: Too many uses for it!
Baking Soda: If for no other reason that to put out grease fires in the kitchen!
Sugar: I don't use much, because I can't, but a little bit in the right places makes a BIG difference.
Salt: See sugar.
Oil: Here there be monsters. Oil comes in several different "flavors" according to what it's squeezed out of. Olive oil, canola (rapeseed) oil, corn oil, peanut oil, and the ubiquitous "vegetable oil," which is usually soybean oil. All I can honestly say is READ. THE. LABEL. One or two of these are always in my kitchen, usually some extra-virgin olive oil and vegetable or corn oil.
Shortening: Again, flavors. I prefer to use vegetable shortening, but if commodities/food pantry trips/whatever hand me lard, I'll use it.
Pepper: Black pepper, like garlic, can save almost any bland dish.
Cocoa Powder: Unsweetened cocoa powder is one thing I definitely can NOT love without. For making beverages, baked goods, stews and chili, it's another one of my go-to items.
CONDIMENTS: The ones I can't live without:
Soy Sauce or Tamari
Peanut Butter (heh)
Honey or Agave Nectar
YMMV, but this is my list. I'm sure there are things I forgot, but if you start with that list, you have several meals on hand. I can think of at least 3 breakfasts, a lunch or two, and with the addition of some different proteins, a few suppers.
Next up: The ToolBox!