Prepare the Meats:
In a skillet, cook the bacon until crispy. Drain and set aside.
In the same skillet, cook the Italian sausage and optional diced onion, breaking the sausage into small pieces as it cooks. Drain any excess fat.
Add the chopped garlic to the sausage mixture and cook for about 1 minute, until fragrant. Remove from heat.
Cook the Pepperoni (Optional):
In a separate pan, cook the sliced pepperoni for a minute or two to crisp it up. Set aside.
Mix the Filling:
In a large bowl, mix together the cooked bacon, sausage, pepperoni, olives (if using), and half of the pizza sauce.
Stuff the Peppers:
Preheat your oven to 400°F (200°C).
Spread the remaining pizza sauce on the bottom of a large baking dish. Place the halved bell peppers on top.
Fill each pepper with the meat and sauce mixture.
Bake:
Cover the dish with foil and bake the stuffed peppers in the preheated oven for about 20 minutes, until the peppers are tender.
Remove the foil, top each pepper with shredded mozzarella, and bake for another 10 minutes, or until the cheese has melted and is bubbly.
