Place potato pieces in a microwave-safe bowl. Cover bowl with plastic wrap; cut a 1-inch slit in the center of the plastic wrap. Microwave at HIGH 10 minutes. Let stand for 2 minutes. Add sour cream and remaining ingredients to bowl; mash with a potato masher. Yield: 4 servings (serving size: about 1 cup).
Omit sour cream and chives; decrease milk to 2 tablespoons and salt to 1/4 teaspoon. Add 3/4 cup plain low-fat yogurt; 1 tablespoon chopped chipotle chile, canned in adobo sauce; and 1/4 teaspoon ground cumin.
Roasted Garlic Variation:
Omit sour cream and chives; increase milk to 3/4 cup. Add 1/4 cup coarsely chopped roasted garlic cloves and 1 tablespoon chopped fresh sage.
Bacon And Cheddar Variation:
Decrease salt to 1/4 teaspoon. Add 1/4 cup shredded reduced fat cheddar cheese and 1 slice center cut bacon, cooked and crumbled; mash with a potato masher to desired consistency.