Creating your Cheesy Hamburger Rice Casserole is straightforward. Just follow these simple steps, and you’ll have a delicious meal ready to enjoy in no time:

1. Preheat the Oven: Set your oven to 350°F (175°C) to get it ready for baking.
2. Cook the Beef: In a large skillet, heat olive oil over medium heat. Add ground beef, diced onion, and minced garlic. Cook until the beef is browned and the onion is translucent.
3. Add Seasonings: Sprinkle in oregano, salt, and black pepper. Stir well to incorporate flavors.
4. Incorporate Rice: Add the uncooked rice to the skillet, mixing it thoroughly with the beef and onion mixture.
5. Mix in Tomatoes and Broth: Pour in the diced tomatoes (with juice) and beef broth. Stir to combine all ingredients together.
6. Add Vegetables: Fold in the frozen mixed vegetables until evenly distributed.
7. Transfer to Baking Dish: Pour the mixture into a greased 9×13-inch baking dish, spreading it evenly.
8. Bake: Cover the baking dish with aluminum foil and bake in the preheated oven for 30 minutes.
9. Add Cheese: After 30 minutes, remove the foil and sprinkle shredded cheddar cheese on top. Return to the oven for an additional 5-10 minutes, until the cheese is melted and bubbly.
10. Serve: Once baked, let it cool for a few minutes before serving. If desired, add dollops of sour cream on top.

This step-by-step guide ensures that you will achieve a flavorful and satisfying casserole effortlessly.