Preheat the oven to 350°F (175°C).

In a skillet over medium heat, brown the ground beef until fully cooked. Drain excess fat.

Add chopped onion and bell pepper to the skillet, cooking until softened.

Stir in the garlic powder, salt, and black pepper.

In a large mixing bowl, combine the cooked beef mixture, uncooked rice, diced tomatoes, and beef broth.

Transfer the mixture to a greased casserole dish and cover with aluminum foil.

Bake in the preheated oven for 30 minutes.

Remove the foil, sprinkle shredded cheddar cheese on top, and bake for an additional 15 minutes until cheese is melted and bubbly.

Let it cool for a few minutes before serving.