1. Preheat the broiler to high heat. Place the whole bell peppers on a baking sheet, then transfer to the oven. Broil, watching very carefully, until the peppers are evenly browned. Let cool slightly, then cut the tops off the peppers and hollow out the insides.

2. In a small skillet, heat the olive oil over medium-high heat. Add the onion and garlic and cook, stirring frequently, just until translucent, about 3 minutes. Transfer the sautéed aromatics to a plate, spreading in an even layer, and set aside to cool slightly.

3. Rip the bread into small pieces, then place in a small bowl. Pour over the milk, toss to combine, and set aside to soak for about 2 minutes.

4. In a large bowl, combine the meatloaf mix, egg, parsley, Parmesan, breadcrumbs, and cooled sautéed aromatics. Wring out the excess milk from the soaked bread and add it to the bowl with the meat mixture. Using your hands, gently mix until just combined. Season with the salt and black pepper to taste.

5. Stuff your hollowed-out bell peppers with the meat mixture, then place them in a shallow pan or pot. Cover the peppers with the marinara sauce, then cover the pan with a lid.

6. Place over medium heat and bring to a simmer, then reduce the heat to low. Cook until the meat mixture is thoroughly cooked, about 45 minutes. Serve!