Sauté the ground beef in a large skillet over medium heat until browned, about 5-7 minutes. Drain excess fat.
Add finely chopped onion and minced garlic to the skillet and sauté for an additional 3-4 minutes until onions are translucent.
Stir in long-grain rice until well-coated with the beef and onion mixture.
Combine French onion soup mix and beef broth, stirring until well combined.
Transfer the mixture to a greased 9x13-inch casserole dish and spread evenly.
Cover the dish tightly with aluminum foil and bake for 45 minutes.
Remove the foil, sprinkle shredded cheese on top, and bake uncovered for an additional 10-15 minutes until cheese is melted and bubbly.
Let the casserole rest for about 5 minutes before serving.
Serve and enjoy your hearty casserole with a fresh salad or crusty bread.