Place 1 cup long-grain white rice in a bowl and cover with cold water and set aside while you prepare everything else. This soaking jumpstarts the cooking process so the rice cooks through in the oven.
Preheat the oven to 400°F. Arrange the 4 green bell peppers, halved lengthwise, seeds removed, cut side up in a deep saute pan or baking dish. Drizzle lightly with oil and roast for 15 minutes until just softened but still holding their shape. Remove and set aside.
In a skillet over medium heat, melt 2 tablespoons butter with 1 tablespoon avocado oil. Add diced 1 yellow onion and cook slowly, stirring occasionally, until golden and sweet, about 15 minutes. Stir in minced 3 garlic cloves and cook until fragrant.
Whisk together ½ cup tomato paste and 1 cup broth or water until smooth. Pour half into the onion-garlic mixture and stir to combine. Reserve the remaining for the smothering sauce.
Drain the soaked rice well. In a large bowl, combine the 2 pounds ground beef, drained rice, onion tomato mixture, 1 tablespoon Italian seasoning, and 2 teaspoons salt. Mix until just combined but do not overwork the meat.
Mound the meat and rice filling generously into each par-roasted pepper half, doming the filling slightly above the rim of the bell pepper. Nestle them snugly back into the pan.
Add 1 cup heavy cream to the reserved tomato sauce mixture and stir together until smooth and creamy. Taste and adjust salt if needed. Pour this creamy tomato sauce evenly over the stuffed peppers. Bake covered (lid or foil) for 35 minutes, then uncover for the last 5 minutes to allow the sauce to reduce and thicken.
Sprinkle shredded 1 cup cheddar cheese evenly over the tops of the peppers. Return to oven for 5-7 minutes until the cheese is melted and bubbly.
Remove from oven and let rest for 5 minutes. Spoon the thickened sauce from the pan over each pepper and garnish with 2 tablespoons fresh parsley.
Notes
Storage: Store leftover bell peppers along with the creamy sauce in airtight container in the refrigerator for up to 4 days. To reheat, place them in an oven-safe dish, spoon some of the sauce over the top, cover with foil, and warm at 350°F for 20 to 25 minutes until heated through. If the sauce has thickened too much in the fridge, add a splash of water or cream before covering. These freeze well. To freeze: arrange fully cooked and cooled peppers in a single layer in a freezer-safe container with sauce poured over them, freeze for up to 3 months, and thaw overnight in the refrigerator before reheating covered in the oven as above.Helpful Tips:
Use long-grain white rice -- no precooking needed. Soaking it in cold water while you prep is enough to jumpstart the process, so it finishes cooking through in the oven without any extra steps ahead of time. But the type of rice is important here if you're soaking it.
Pre-roast the peppers before stuffing. Skipping this step means the pepper and the filling won't finish at the same time -- you'll either end up with undercooked pepper or overcooked meat. So be sure to pre-roast for 15-20 minutes.
Dome the filling generously above the rim. The meat shrinks slightly as it cooks, so piling it high gives you a full, hearty result rather than a sunken filling.
If the rice or filling looks undercooked, cover the pan. Place the lid on your pan or cover tightly with foil and return to the oven for another 10 minutes -- the trapped steam finishes the job.
The information shown above is an estimate provided for your convenience by an online calculator. It should not be considered as a substitute for a professional nutritionist's advice. Please see our complete Nutritional Information Disclaimer.