6 medium onions, or about 3 pounds
1 1/2 sticks butter
8 slices bacon
3/4 cup olives, sliced
1 1/2 cups smoked gouda cheese, grated (may substitute other cheeses)
Slice onions 1/8 inch thick. Place onions and butter in heavy pan, salt to taste. Cook on low heat, stirring often until onions are translucent, tender and golden brown. Drain excess fat. Onions may be kept in refrigerator for up to 5 days. To rewarm, heat in heavy pan over medium-low heat.
Chop bacon and scramble fray until crisp. Drain excess fat. Stir bacon into onions. Cut rolls in half, keeping halves connected. Place rolls open on cookie sheet. Spread halves with onion, bacon mixture. Sprinkle with sliced olives and grated cheese. Bake at 400 degrees for 20 minutes or until cheese is melted and golden brown. While rolls are still warm, fold halves back together to form a closed sandwich.