In a large skillet over medium heat, add the lean ground beef, cooking until it's mostly browned, about 5–7 minutes. Add chopped yellow onion, stirring frequently until it becomes translucent, about 3 minutes, then mix in minced garlic and sauté for another minute until fragrant. Drain excess grease before transferring the mixture to your slow cooker.

In the slow cooker, combine the cooked beef mixture with frozen diced potatoes, sweet corn, and the entire can of undrained Rotel diced tomatoes with green chilies. Ensure the ingredients are well distributed.

In a separate bowl, whisk together the condensed cream of mushroom soup and beef broth, creating a smooth sauce. Pour this mixture evenly over the layered ingredients in the slow cooker.

Sprinkle in the dried paprika, chili powder, garlic powder, black pepper, and salt. Gently stir the mixture to incorporate the seasonings.

Cover the slow cooker with its lid and set it to cook on LOW for 6–8 hours or HIGH for 3–4 hours, until the potatoes are tender.

Thirty minutes before serving, sprinkle the shredded sharp cheddar cheese on top of the casserole. Re-cover the slow cooker.

Once done, give the casserole a gentle stir if desired, and top with additional cheese, crispy fried onions, or crumbled bacon before serving warm.