Step 1: Prepare the Bell Peppers

1. Preheat Oven: Adjust your oven rack to the middle position and preheat to 400°F (200°C).
2. Cut and Clean: Slice the bell peppers in half lengthwise, from stem to bottom. Use a small knife to carefully remove the seeds and white membranes from each half. The goal is to create 12 stable “boats” for your filling.
3. Pre-Bake the Peppers: Place the pepper halves, cut side up, in a large 9×13 inch baking dish or on a baking sheet. Drizzle them lightly with about 1 tablespoon of olive oil and sprinkle with a pinch of salt and pepper. Bake for 15-20 minutes. This pre-baking step is crucial—it softens the peppers so they become tender and sweet, and it helps prevent the final dish from becoming watery. Once done, remove them from the oven and set them aside. Reduce the oven temperature to 375°F (190°C).

Step 2: Create the Savory Filling

1. Sauté Aromatics: While the peppers are pre-baking, heat the remaining 1 tablespoon of olive oil in a large skillet or Dutch oven over medium-high heat. Add the finely chopped onion and cook for 5-7 minutes, stirring occasionally, until it becomes soft and translucent. Add the minced garlic and cook for another minute until fragrant.
2. Brown the Meat: Add the ground beef to the skillet. Use a wooden spoon or spatula to break it up into smaller crumbles. Cook until the beef is fully browned and no pink remains, which should take about 8-10 minutes. Drain off any excess grease from the pan.
3. Incorporate Vegetables and Seasonings: Add the riced cauliflower to the skillet with the beef and onions. Cook for 5-7 minutes, stirring frequently, until the cauliflower has softened and released some of its moisture. This step is important for developing flavor and preventing a soggy filling.
4. Add Sauces and Spices: Stir in the drained diced tomatoes, tomato sauce, Italian seasoning, smoked paprika, salt, pepper, and Worcestershire sauce (if using). Bring the mixture to a simmer and let it cook for about 5 minutes, allowing the flavors to meld together. The filling should be thick and savory.
5. Stir in the Cheese: Remove the skillet from the heat. Stir in 1 cup of the shredded mozzarella cheese. This makes the filling extra rich and helps it bind together beautifully. Taste the filling and adjust seasonings if needed—it should be well-seasoned and delicious on its own.

Step 3: Assemble and Bake

1. Fill the Peppers: Carefully drain any water that may have collected in the bottom of the pre-baked pepper halves. Arrange them snugly in your 9×13 inch baking dish. Generously spoon the meat and cauliflower mixture into each pepper half, mounding it slightly on top.
2. Add Topping: If you have any leftover tomato sauce, you can pour a thin layer into the bottom of the baking dish around the peppers to keep them moist. Sprinkle the remaining 1 cup of shredded cheese evenly over the tops of all the stuffed peppers.
3. Bake to Perfection: Cover the baking dish loosely with aluminum foil. This prevents the cheese from burning before the peppers are heated through. Bake at 375°F (190°C) for 20-25 minutes.
4. Brown the Cheese: Remove the foil and continue to bake for another 10-15 minutes, or until the filling is bubbly and heated through, and the cheese on top is melted, golden, and slightly browned. For an extra crispy, browned top, you can place the dish under the broiler for 1-2 minutes at the very end—watch it carefully to prevent burning!
5. Rest and Garnish: Let the stuffed peppers rest for at least 5-10 minutes before serving. This allows them to set up and makes them easier to serve. Garnish with fresh chopped parsley for a pop of color and freshness.