In a covered steamer, steam the potatoes over boiling water, until tender when pierced, 30 to 40 minutes. When cool enough to handle, peel, then cut into 1/2 to 3/4 inch cubes. In a large bowl, stir together potatoes, celery, onion, vinegar, salt and pepper. Add relish, egg whites and mayonnaise and stir gently to combine. Taste and adjust with salt and/or pepper. Transfer to serving bowl and sprinkle with parsley. Tip: Make this sald a day ahead and refrigerate it. Taste before serving, and adjust the salt, pepper, and/or vinegar. Serving size: 1 cup. 84 calories, 0.17 grams fat, 0 cholesterol, 523 mg sodium. >From "Everyday Cooking with Dr. Dean Ornish: 150 Easy Low-Fat, High-Flavor Recipes, " (Harper Collins, $23,

fat.