In a large skillet over medium heat, brown the ground beef for about 6-8 minutes, breaking it apart as it cooks until it’s no longer pink. Once browned, drain excess grease, and set the cooked beef aside.

In the same skillet, add a drizzle of oil or a pat of butter and sauté the chopped onion over medium heat for 5-7 minutes, stirring occasionally until soft and golden brown.

In a large mixing bowl, combine the cooked ground beef, sautéed onion, rice, French onion soup, garlic powder, salt, and pepper. Stir well for 2-3 minutes until completely combined.

Preheat your oven to 350°F (175°C). Grease a 9x13-inch casserole dish and transfer the beef and rice mixture into it, spreading evenly. Sprinkle a generous layer of shredded cheese on top.

Cover the casserole with aluminum foil and bake in the preheated oven for 30 minutes. Then, remove the foil and bake for an additional 10-15 minutes until the cheese is melted and bubbly.

Let the casserole rest for about 5 minutes before slicing. Serve warm.