Step 1

Preheat the oven to 350 degrees F (175 degrees C). Bring a shallow pot of water to a boil. Immerse the bell peppers in boiling water for 3 minutes. Remove from the water, and drain. Place the peppers, cut side up, in a lightly greased 9x13 inch baking dish.

Step 2

In a medium bowl, combine the ground beef, onion and rice. Season with salt, pepper and garlic powder; mix with your hands until blended. Divide into 8 portions and mold into elongated patties. Stuff one patty into each pepper half. Pour the tomato soup over the stuffed peppers, dividing evenly. Top each one with a slice of tomato, pressing down to adhere. Cover with aluminum foil.

Step 3

Bake for 1 hour in the preheated oven, then remove the aluminum foil. Top with Cheddar cheese and return to the oven. Bake until cheese is melted, about 5 more minutes.