Preheat the oven to 350°F (175°C).

In a large skillet, brown the ground beef over medium heat. Drain excess fat.

Add diced onion and minced garlic to the skillet and sauté until the onion is translucent.

Stir in the uncooked rice, diced tomatoes, beef broth, Italian seasoning, salt, and black pepper. Bring to a boil.

Reduce heat and let simmer for about 10 minutes, or until the rice is partially cooked.

Add the chopped bell peppers to the skillet and mix well.

Transfer the mixture to a casserole dish and spread evenly.

Sprinkle shredded cheese on top.

Cover with foil and bake in the preheated oven for 30 minutes.

Remove foil and bake for an additional 10-15 minutes, until cheese is bubbly and golden.