Prick Potatoes with fork to allow steam to escape. Bake potatoes in 220ºC oven until tender, about 1 hour. Cool slightly Cut each potatoe lengthwise into halves, scoop out insides, leaving a 1 cm shell. Spread inside of shells with margarine or butter, sprinkle with salt. Cut each potatoe into six pieces, sprinkle with cheese and bacon. Set oven control to broil or 290ºC . Broil potatoe pieces about 13 cm from heat until cheese is melted, about 2 minutes. Makes 48 appetizers.