Preheat oven to 350°. In a small skillet, cook pancetta over medium heat until browned, stirring occasionally. Remove with a slotted spoon; drain on paper towels., Meanwhile, cut a thin slice off top of each roll. Hollow out bottom of roll, leaving a 1/2-in.-thick shell (save removed bread for another use); place shells on an ungreased baking sheet., Add mushrooms and pancetta to bread shells. Carefully break an egg into each; sprinkle eggs with salt and pepper. Sprinkle with cheese. Bake 18-22 minutes or until egg whites are completely set and yolks begin to thicken but are not hard.