Instructions:
- Preheat oven to 375°F (190°C). Slice the peppers in half lengthwise, remove seeds and membranes. Place pepper halves cut-side up in a baking dish.
- Par-bake the peppers: Add ¼ inch of water to the bottom of the dish and bake for 10 minutes. Remove from oven and drain water.
- In a skillet over medium heat, melt butter. Add onion and sauté until translucent (about 5 minutes). Add garlic and cook for 1 minute until fragrant.
- Add ground beef to the skillet. Break up the meat and cook until fully browned. Drain off any excess fat.
- Transfer the browned meat mixture to a large mixing bowl. Add the cooked rice, tomato sauce, fresh parsley, beaten egg, salt, and pepper. Mix thoroughly until just combined.
- In the skillet, whisk together the canned diced tomatoes, broth, oregano, salt, and pepper to create the sauce base. Pour this sauce evenly into the bottom of the prepared baking dish.
- Generously fill each pepper half with the meat and rice mixture, mounding the filling slightly on top.
- Arrange the stuffed peppers on top of the sauce in the baking dish. Cover the dish tightly with aluminium foil.
- Bake covered for 30 minutes. Remove the foil and bake for an additional 10–15 minutes, or until the filling is piping hot and the tops are slightly browned.
- Let rest for 5 minutes before serving. Garnish with fresh parsley.