Smoked Gouda and Bacon Stuffed Mushrooms

Bahan-bahan (8 porsi)

• 1 lb white or brown mushrooms
• 6 -8 oz bacon (chopped)
• 1 small/medium onion (chopped)
• 2 cups 1/3 lb smoked gouda cheese, finely grated
• 1 cup mozzarella cheese (finely grated)