This is a list of staples I keep in my vegan kitchen on a regular basis. When I first went vegan I built this up gradually as I branched out and learned new recipes:
Vinegars (usually rice and cider vinegar and sometimes balsamic)
lemon juice and lime juice
soy sauce or tamari (for making dishes for my gluten free Mom)
vegan mayonnaise (Just Mayo or Vegannaise)
salsa
dijon mustard
organic catsup
applesauce
flaxseeds/ground flaxmeal
unsweetened coconut flakes
vital wheat gluten
cornmeal or polenta
oats
whole wheat flour, white spelt flour, whole wheat pastry flour
white rice flour and brown rice flour
sorghum flour
chickpea flour (awesome to have around to make chickpea flour omelets)
baking soda and baking powder
tapioca starch, cornstarch
maple syrup
blackstrap molasses (great source of calcium and iron and goes well in hot cereal, homemade Asian sauce, smoothies, baking bread etc)
tahini
peanut butter (just peanuts)
sesame seeds, pumpkin seeds, sunflower seeds (shelled)
brazil nuts, almonds, walnuts, pecans
nutritional yeast flakes (found in bulk section of natural food stores)
buckwheat groats, oat groats, millet, brown rice, jasmine rice, couscous, quinoa, bulgur wheat (great for making taco "meat", spaghetti sauce "meat", sloppy joe "meat" etc as the texture is similar to ground beef and it absorbs other ingredients well)
spaghetti, whole wheat penne pasta, buckwheat soba noodles (without egg), udon noodles
cans of tomato paste, tomato sauce, diced or stewed tomatoes
dried lentils (brown, red)
dried split peas (green, yellow)
cans of chickpeas, white beans, black beans, kidney beans (sometimes dry too)
cans of pineapple
cans or artichoke hearts
canned pumpkin (great in place of egg for some baking and for smoothies or pancakes etc)
turbinado sugar
agar flakes (if you like to make things that "gel", this works beautifully in place of gelatine)
spices like cumin, chili powder, garlic powder, cayenne, turmeric, paprika, garam masala, coriander, oregano, basil, dill seed or weed, thyme, black pepper, onion powder, marjorum, mustard powder
vegan commercial bread on occasion (Rudi brand or Ezekiel/Food For Life) or I make my own more often
Frozen mixed vegetables, bananas I freeze in chunks and keep in freezer bags, frozen berries in winter months, frozen peas and limas
tempeh, tofu (I almost always keep a package of tempeh on hand but tofu is something I buy less often)
plant milks (almond, soy usually but have tried oat, hemp etc and used to make my own flaxseed milk and almond milk)
sweet potatoes (great in soups, burritos, casseroles, mashed with pineapple or coconut etc)
potatoes (red or russet)
a variety of leafy greens always on hand (collards, kale, bok choy, spinach, turnip greens, romaine etc) (good for smoothies, salads, in sandwiches, wraps, soups etc)
bell peppers
cucumbers
zucchini, yellow squash
winter squash (butternut, acorn)
green beans
snap peas
mushrooms
tomatoes
jicama
celery
carrots
onions
asparagus or brussel sprouts
broccoli always on hand
apples
oranges
bananas
seasonal fruits (berries, plums, peaches...)
cantaloupe or pineapple
I love sweet potatoes, so I did a lot of stuff with them in the beginning, like making sweet potato pancakes (mashed sweet potato is a great binder and pancakes are so easy to do without eggs or dairy), roasted sweet potato fries and roasted chickpeas, sweet potato and peanut butter soup.
Another easy favorite of mine is sauteeing some diced red potatoes, sauerkraut, savoy cabbage, diced fresh apple, and navy beans all together in a large nonstick skillet with a little water. I add caraway seeds also, and a splash of cider vinegar. This is a hearty meal all in itself, and takes less than 30 minutes to make.
Once you find a decent vegan bread (or a good recipe to make your own bread) stuff like beans on toast is great for breakfast, or chickpea salad sandwiches for lunch (mashed chickpeas, onion, celery, vegan mayo such as Just Mayo or Vegannaise, and black pepper spread on your slices of bread).
Soups are very easy to work with and hard to mess up. I love a simple bean/vegetable/leafy green soup. Such as black beans, zucchini, and tomato soup. Or pureed carrot/white bean curry soup. Cream of broccoli soup can be made by adding potatoes and almond milk and blending your soup once your broccoli and potatoes are simmered in water and soft.