I hate to see salad go to waste, but leftover dressed salad is fit only for the compost bin. However, I also hate to serve dressing on the side – it never tastes just right when it’s simply dribbled over salad greens on a diner’s plate. Solution: Keep a medium tossing bowl and dressing beside the undressed salad.  That way, diners can take any amount they want, add dressing to taste, toss and self-serve. Afterwards, I transfer the leftover undressed salad to a storage tub or zip-lock bag, then refrigerate it. If the salad includes tomatoes, however, I usually discard them beforehand. The cold is disastrous for tomatoes. Salad dressing tips, pg. 462 in 12, 167 Kitchen and Cooking Secrets.