This one is easy, and leftovers are good cold.
Cooked spaghetti, small box
6-8 plum tomatoes, diced
2-4 cloves garlic, pressed
1/4 - 1/2 cup chopped fresh basil (dried doesn't give the same fresh flavor)
1/2 cup vegetable broth (more if you like it soupier)
salt and pepper to taste
Warm the tomatoes, garlic, and vegetable broth and toss with the spaghetti.
Salt and pepper to taste and serve hot or cold.