Preheat your oven to 375°F (190°C). Arrange the bell peppers cut side up in a baking dish or on a rimmed tray. This allows them to roast evenly and hold their shape while stuffing.

Heat the olive oil in a large skillet over medium heat. Add the diced onion and sauté until softened, about 4–5 minutes. Stir in the minced garlic and cook for another minute until fragrant.

Add the ground beef to the skillet and cook, breaking it up with a wooden spoon, until browned and no longer pink—around 5–6 minutes.

Stir in the cooked brown rice, diced tomatoes, tomato paste, oregano, and paprika. Let the mixture simmer for about 4–5 minutes, allowing the flavors to blend and the sauce to reduce slightly. Taste and season with kosher salt and pepper.

Spoon the beef and rice mixture into each prepared bell pepper, packing it down gently. Fill each pepper to the top for a hearty serving.

Place the stuffed peppers in the oven and bake for 10–12 minutes until the peppers are starting to soften.

Remove from the oven, sprinkle each pepper generously with shredded cheese, and return to bake for another 5–7 minutes, or until the cheese is melted and bubbly.

Finish with a sprinkle of freshly chopped parsley and serve warm. Enjoy your delicious and satisfying stuffed bell peppers!