Preheat the oven to 350°F (175°C).
In a large skillet over medium heat, cook the ground beef until browned, stirring frequently. Drain any excess fat.
Add the diced onion and minced garlic to the skillet. Cook for about 3-4 minutes until the onion is translucent.
Stir in the uncooked rice, beef broth, diced tomatoes, frozen corn, oregano, paprika, salt, and pepper. Mix well to combine.
Bring the mixture to a gentle boil, then reduce the heat and let it simmer for about 10 minutes, allowing the rice to absorb some of the liquid.
Remove the skillet from heat and stir in 1 cup of shredded cheddar cheese until melted and well combined.
Pour the mixture into a greased 9x13 inch baking dish. If desired, sprinkle the top with shredded mozzarella cheese for an added cheesy layer.
Cover the baking dish with aluminum foil and bake in the preheated oven for 20 minutes.
Remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and golden brown.
Let it cool for a few minutes before serving. Enjoy your cheesy hamburger rice casserole!