1Preheat your oven to 375°F (190°C).
Cut the tops off the bell peppers and remove the seeds and membranes. Set aside.
In a large skillet, cook the ground beef over medium heat until browned. Drain any excess fat.
Add the diced onions to the skillet and cook until they are translucent.
Stir in the Rotel tomatoes, cooked rice, and garlic powder. Cook for an additional 5 minutes, stirring occasionally.
Remove the skillet from heat and stir in half of the shredded mozzarella cheese.
Stuff each bell pepper with the beef mixture and place them in a baking dish.
Sprinkle the remaining shredded mozzarella cheese on top of the stuffed peppers.
Cover the baking dish with aluminum foil and bake in the preheated oven for 30 minutes.
Remove the foil and bake for an additional 10-15 minutes, or until the cheese is melted and bubbly.
Remove from the oven and let cool for a few minutes before serving.