Onions (white or yellow)
Rice (Arborio, white long grain)
Flour (unbleached all-purpose)
Sugar (preferably raw, but I won't bite your nose off it it's refined; white granulated; also brown sugar)
Dried pasta (MC's choices: linguine, capellini (angel hair), penne)
Salt (table salt is fine, but sea salt and kosher salt are better)
Herbs: Basil, marjoram or oregano, parsley, rosemary, sage, thyme.
Spices: Black pepper, ground cinnamon, ground cloves, ground cumin, garam masala.
Frozen meats (chicken is simple)
Canned tomato paste
Mushrooms, fresh or canned
Vinegar (distilled white, and balsamic)
Unsweetened cocoa powder
Dairy: Milk, yoghurt, butter.
Cheeses: Mozzarella, cheddar, parmasan.
Canned beef, chicken, and vegetable broth, or stock cubes
Mustards: Prepared yellow, prepared dijon.
Fresh and raw is /always/ preferable, in any food.
Everything is subject to your own tastes, of course. Lazy fish-eating vegetarians, regular vegetarians and vegans know what to leave out, or substitute. (Okay, I suppose I shouldn't leave out the fruitarians, paleodiet people, and raw foodists. I can leave out the breatharians, though, right?) Vegetarians will want to omit the Worcestershire sauce, as it contains anchovies.
On herbs: It is best to have fresh herbs, but unless you grow them yourself, this just isn't practical. Dried is fine.
On cheeses: These can be frozen, and are still easy to use if first grated.
Don't let this seem overwhelming. Much of the food will keep for a long time, and once you have them, you have them. They will eventually be useful.
*with an Italian/English/Southern US/Indian bias because MC <3 Italian food and is fairly English, definitely has southern US influence, and Indian because MC occasionally cooks for/with adiligode.
More astrology coming soon... sorry for the delay, I suck at commitment...