Serious Eats - seriouseats.com

Since pasta and beans are so cheap try combining them. In a tablespoon of olive oil slightly cook about 3 cloves of garlic. Add one or two cans of pinto beans and chopped up broccoli and serve over a pound of short pasta (penne or rigatoni). As always puts some parmesean cheese on top. $4 total

Cook about 4 cloves of garlic and 2 or 3 whole pepperoncini (probably about 1 teaspoon of red pepper flakes) in a half cup of olive oil, serve over pasta. $3 total

1 Onion cooked in half a stick of butter, add a can or 2 of tuna and serve over pasta. $5 total

3 cans of tomatoes (15 ounces each) cooked with either garlic or onions (not both), basil, salt, pepper, a dash of red wine vinegar and a tablespoon of sugar. $4 total

Throw some Edam or Gouda cheese in with pasta and nothing else. $5 total