Step 1: Prepare the Peppers

• Preheat your oven to 400°F (200°C).
• Wash and dry the bell peppers. Slice them in half from stem to bottom. Use a spoon to carefully scoop out the seeds and white membranes.
• Place the pepper halves, cut-side up, in a 9×13 inch baking dish or on a baking sheet lined with parchment paper.
• Drizzle the peppers lightly with olive oil and a sprinkle of salt and pepper.
• Pre-bake the empty pepper halves for 15-20 minutes. This crucial step softens them and helps release excess moisture, preventing a watery final dish. Once done, remove them from the oven and set them aside.

Step 2: Cook the Pizza Filling

• While the peppers are pre-baking, heat 1 tablespoon of olive oil in a large skillet or pan over medium-high heat.
• Add the chopped yellow onion and cook until it becomes soft and translucent, about 3-4 minutes.
• Add the minced garlic and cook for another minute until fragrant, being careful not to burn it.
• Add the ground beef or Italian sausage to the skillet. Use a spatula to break the meat apart and cook until it’s browned and cooked through, approximately 7-8 minutes.
• Crucial Step: Once the meat is cooked, drain off any excess grease from the pan. This is vital for preventing the stuffed peppers from becoming oily.
• Return the skillet to the heat and stir in the Italian seasoning, dried oregano, and optional red pepper flakes.
• Pour in the pizza sauce and stir everything to combine. Let the mixture simmer for 2-3 minutes to allow the flavors to meld together.
• Turn off the heat. Stir in 1 cup of the shredded mozzarella cheese and half of the pepperoni slices. The cheese will become melty and help bind the filling together.

Step 3: Stuff and Bake the Peppers

• Carefully spoon the meat and sauce mixture evenly into each of the pre-baked pepper halves. Fill them generously, mounding the filling on top.
• Arrange the stuffed peppers snugly in your baking dish. This helps them stay upright during baking.
• Top each pepper half with the remaining 1 cup of mozzarella cheese, followed by the rest of the pepperoni slices.
• Place the baking dish back into the 400°F (200°C) oven. Bake for 15-20 minutes, or until the peppers are fully tender and the cheese is melted, bubbly, and starting to brown.
• For an extra golden, pizzeria-style top, you can switch the oven to the broil setting for the last 1-2 minutes. Watch it very closely to prevent burning.

Step 4: Garnish and Serve

• Remove the baking dish from the oven and let the Pizza Stuffed Peppers rest for a few minutes. This allows the filling to set and makes them easier to handle.
• Garnish with a sprinkle of freshly chopped parsley or basil and a dusting of grated Parmesan cheese.
• Serve hot and enjoy the best of both worlds!