Preparation and Cooking

• Preheat the oven to 375 degrees F (190 degrees C).
• Melt butter in a skillet over medium heat. Add onion and mushrooms; season with salt and black pepper. Cook and stir until mushrooms are dark and juicy, about 5 minutes. Off heat, stir in bread crumbs. Set aside.
• Place chicken breasts, one at a time, between 2 sheets of heavy plastic on a solid, level surface. Firmly pound breasts with the smooth side of a meat mallet to a ¼-inch thickness.
• Lay 1 breast onto a work surface; place 1 slice ham on top. Spoon about 3 tablespoons mushroom mixture onto ham; top with about 2 ½ tablespoons Havarti cheese. Roll breast to enclose filling. Firmly wrap roll with 2 strips bacon; secure with toothpicks. Place roll in a 9x13-inch baking dish. Repeat with remaining breasts, ham, mushroom mixture, Havarti cheese, and bacon.
• Bake in the preheated oven until chicken is no longer pink and fillings melted and hot, about 35 minutes.
• An instant-read thermometer inserted into centers of rolls should read at least 165 degrees F (74 degrees C).
• Remove rolls from the oven. Carefully set an oven rack about 6 inches from the heat source. Turn on the broiler and return rolls to the oven. Broil until bacon is brown, 5 to 10 minutes.