Mushroom Bacon Stuffing

• 12 skillet over heat
• 1 onion
• 1 egg
• 160 gr sized mushrooms
• 55 gr butter
• 55 gr bacon drippings from skillet
• 1 gr sage leaves (dried)
• 20 slices firm textured bread (sliced white)
• 6 slices bacon (sliced)
• 3 slices celery ribs