Prepare the peppers. Properly wash them and trim about ⅛-inch off the bottom so they sit upright. Cut the top of each pepper, scoop out the seeds, and clean the membranes as much as you can. Chop the rest of the pepper tops, as we will need them for later.
Precook the peppers by putting them in a microwave-safe bowl with a cup of water. Microwave for about 10 minutes on high power. Once cooked, uncover them, and let them sit. Note: to avoid watery peppers you can put your peppers in a preheated oven at 350°F for about 10 minutes.
Start cooking the meat. Heat a large skillet with 2 tablespoons of oil over medium-high heat. Cook the beef in an even layer and leave for about 3 minutes until it’s lightly brown in the bottom side. Toss the beef and break up any clumps, scrapping up any browned bits. Cook for another 6-8 minutes until it is lightly brown. Once it’s cooked, transfer the beef to a large bowl with a slotted spoon, so it doesn’t retain too much liquid.
Heat the remaining 1 tablespoon of olive oil in the same frying pan at medium heat and add the reserved chopped peppers, garlic, thyme, onions, 4 teaspoons of salt, and ½ teaspoon of pepper. Cook for 10-12 minutes, stirring occasionally until the veggies are tender, but not brown. After that add the chopped tomatoes or any other tomato substitutes you like, and cook for 7 minutes stirring occasionally until all the liquid evaporates. Add the wine and continue stirring for another 6-8 minutes until the mixture is very thick and brick red-colored.
Add the broth to the tomato mixture and get it to boil. Once boiled, transfer it to the beef and stir in the precooked rice, until it is completely combined. Season this wet mixture with pepper and salt.
Put the peppers cut-side up in a baking pan and stuff them. Place them in a preheated oven at 450°F. After baking for 15 minutes, take the peppers out and top them with your cheese mixture (use a fast-melting cheese like mozzarella, cheddar, or Parmesan), and bake for another 10-12 minutes until the cheese is melted and brown. Note: don’t overstuff the peppers, as it could split the sides and make peppers to fall apart.
Take your stuffed peppers from Ina Garten and serve them with your favorite side dish.