Lettuce Preparation: 30 minutes including cooking potato plus chilling. Cook potato in its jacket until just tender. Cool until it can be handled, peel and dice into a bowl. You should have about 1 cup. Stir oil, vinegar, and salt together and pour over hot potato, tossing lightly. Cool. Add celery, green pepper, pimento, olives and onion. Stir mayonnaise and cottage cheese together, add to salad and toss lightly. Chill well. Serve on lettuce.