1Heat oven to 375°F. Pierce potatoes to allow steam to escape. Bake 1 hour to 1 hour 15 minutes or until tender. Let stand until cool enough to handle. Cut potatoes lengthwise into fourths; carefully scoop out pulp, leaving 1/4-inch shells. Save potato pulp for another use.
2Set oven control to broil. Place potato shells, skin sides down, on rack in broiler pan. Brush with butter.
3Broil with tops 4 to 5 inches from heat about 5 minutes or until crisp and brown. Sprinkle with cheese. Broil about 30 seconds or until cheese is melted. Serve hot with sour cream and onions.