[jb9]

good olive oil
onions
garlic
parsley (flat leaf not the curly kind)
tomatoes (canned are ok)
rosemary
oregano
basil
bay leaf
salt and pepper

Basically in that order. Saute onions and garlic in olive oil. Simmer everything at least an hour. The longer you simmer it, the thicker/richer the sauce will be.

You can use dried or fresh spices, but don't use dried garlic. If the sauce isn't dark enough, add some tomato paste. If it is boring, add more spices (possibly some crushed red pepper). If it is oily, add more tomatoes. Don't eat the bay leaf.