6 bell peppers – tops cut off, seeds and membranes removed
1 cup long-grain white rice – rinsed
1.75 cups water
2 tbsp olive oil
1 onion – finely chopped
3 cloves garlic – minced
1.5 pounds ground beef
28 ounces canned crushed tomatoes
1 tsp dried oregano
2 tsp kosher salt
1 tsp black pepper – ground
0.25 cup fresh parsley – chopped
1.5 cups mozzarella cheese – shredded
Instructions
Heat the oven to 375°F (190°C).
Prepare the bell peppers: trim the tops, remove seeds and membranes, and arrange cut-side up in a 9x13-inch baking dish. Cover tightly with foil and bake until slightly softened, 10 minutes. Remove and set aside.
Cook the rice: combine the long-grain white rice and water in a small saucepan. Bring to a boil, then reduce heat to low, cover, and cook until tender, 15–18 minutes. Remove from heat and let stand, covered, 5 minutes.
Heat the olive oil in a large skillet over medium heat. Add the onion and cook, stirring, until translucent, 5–7 minutes. Stir in the garlic and cook until fragrant, 30 seconds.
Add the ground beef and cook, breaking it up with a spoon, until no pink remains, 6–8 minutes. Spoon off excess fat if needed.
Stir in the canned crushed tomatoes, reserving 1 cup for the baking dish; add the dried oregano, kosher salt, and black pepper. Simmer, stirring occasionally, until thickened and saucy, 5–7 minutes.
Fold the cooked rice and fresh parsley into the beef-tomato mixture until evenly combined.
Assemble: spoon 1/2 cup of the reserved crushed tomatoes over the bottom of the baking dish. Divide the beef-rice filling among the peppers, packing it in and mounding slightly. Spoon the remaining reserved crushed tomatoes around the peppers.
Cover the dish tightly with foil and bake until the peppers are tender when pierced and the filling is hot and bubbling, 30–35 minutes.
Uncover, top evenly with the mozzarella cheese, and bake until melted and lightly browned in spots, 8–10 minutes.