Orange–Red Onion–Cress Salad

Wash the lettuce and watercress. Drain very well and pat dry between towels. [For large amounts, I use a double thickness of bed sheet over a large table, or even a clean floor.] Be sure the lettuce and cress are clean and dry, then pick over and tear into bite-sized pieces. Place in a salad bowl. [For large amounts, keep the greens in plastic garbage bags until needed.] Just before serving, ad