Leftover Tomato Vinaigrette — Dorie Greenspan is the master of thrifty vinaigrettes. I'm a big believer in her Mustard Bottle Vinaigrette (where you pour vinegar and oil into an almost empty mustard jar and shake it up), and now I can't wait to try her Leftover Tomato Vinaigrette (where you take leftover tomato salad and whir it up to make a dressing).