In a skillet over medium heat, brown the ground beef until fully cooked, about 5-7 minutes. Drain excess fat, then add chopped onion and sauté until soft and translucent, roughly 3-4 minutes. Stir in minced garlic, paprika, and chili powder; cook for an additional minute until fragrant.

In a mixing bowl, combine the condensed cream of mushroom soup with beef broth or milk. Whisk until smooth and creamy.

Lightly grease the bottom of a slow cooker with cooking spray. Layer half of the frozen diced potatoes evenly.

Spread half of the beef mixture over the potatoes. Then, distribute whole kernel corn and Rotel diced tomatoes with green chilies on top. Sprinkle shredded cheddar cheese over the layer.

Stack the remaining frozen diced potatoes on top, followed by the rest of the beef mixture, another cup of corn, and the remaining diced tomatoes.

Pour the last of the creamy soup mixture over the casserole layers.

Cover the slow cooker and set on LOW for 6-8 hours or HIGH for 3-4 hours. The casserole is ready when the potatoes are tender.

In the last 10-15 minutes of cooking, sprinkle the remaining cheese on top, cover again and let the cheese melt.

Let the casserole rest for about 10 minutes before serving. Garnish with optional parsley flakes.