In a skillet set over medium heat, cook the ground beef until fully browned, breaking it into small crumbles as it cooks. Once done, drain off the excess grease so the casserole does not become oily during the slow cooking process.
While the beef is cooking, wash and chop the potatoes into bite-sized pieces. Try to keep the pieces close in size so they soften evenly and finish cooking at the same time.
Spread the chopped potatoes across the bottom of the crockpot in an even layer. Add the browned ground beef over the potatoes, then scatter the drained kidney beans and corn across the top.
Pour the tomato sauce evenly over everything in the crockpot. Sprinkle the garlic powder, onion powder, smoked paprika, salt, and black pepper across the top so the seasoning distributes as the casserole cooks.
Cover the crockpot with the lid and cook on low for 6 to 8 hours or on high for 3 to 4 hours. The casserole is ready when the potatoes are fork tender and the mixture is hot and well combined.
About 30 minutes before serving, sprinkle the shredded cheese over the top. Cover again and let the cheese melt fully into the casserole.
Once the cheese has melted, check the seasoning and adjust with a little more salt or pepper if needed. The potatoes can absorb a lot of flavor, so a final taste helps balance everything before serving.
Spoon the casserole into bowls or onto plates and top with sour cream and chopped chives if desired. Serve it hot for a simple, hearty meal that works well for busy weeknights or relaxed family dinners.