Tomato Paste
Pour a can (8 or 15 ounces) of tomato sauce into a saucepan and bring it to a brisk simmer over medium heat. Simmer, stirring constantly, for about 7 minutes, or until reduced by about two-thirds. You should have about 3 to 4 ounces of tomato paste from an 8 ounce can, or about 6 or 7 ounces from a 15-ounce can.