In a large skillet over medium heat, brown the ground beef until fully cooked, about 5-7 minutes. Be sure to drain any excess fat for a less greasy dish.

Add the diced onions and minced garlic to the skillet; sauté for 3-4 minutes until the onions become soft and translucent, infusing delicious flavors.

In a large bowl, mix the cooked beef mixture with the corn, cream of mushroom soup, sour cream, half of the shredded cheddar, salt, pepper, and any optional spices until everything is well combined and creamy.

Grease a 9x13-inch baking dish generously. Layer half of the frozen diced potatoes on the bottom, then spread the beef mixture over it. Top with the remaining potatoes and sprinkle the rest of the cheddar cheese on top.

Cover the dish with foil and bake in a preheated oven at 375°F (190°C) for 30 minutes. Then, uncover and bake for an additional 10-15 minutes until the cheese is melted and bubbly, turning a beautiful golden color.

Let the casserole sit for 5-10 minutes before serving to help it hold its shape; this waiting time ensures a delightful presentation.