Preheat oven to 375°F (190°C). Lightly grease a 9×9-inch baking dish with nonstick spray or oil.

Brown ground beef in a skillet over medium heat, breaking it up as it cooks (6–8 minutes). Drain excess grease.

Mix cooked beef, cream of mushroom soup, rice, and frozen vegetables in the skillet or a bowl until well combined.

Transfer mixture to the baking dish and spread evenly. Top with shredded cheddar (add extra if desired).

Bake for 20–25 minutes until hot and bubbly. For a golden top, broil for 1–2 minutes—watch carefully.

Cool for 5 minutes, then serve warm with your favorite side or a fresh salad.