In a skillet over medium heat, brown the ground beef with the onion, garlic, and bell pepper until the meat is fully cooked and the vegetables are tender. Drain any excess fat.
In a small bowl, mix together the cream of mushroom soup, milk, salt, pepper, and paprika.
Layer half of the potatoes in the bottom of a slow cooker. Top with half of the meat mixture and half of the soup mixture. Repeat the layers with the remaining potatoes, meat, and soup mixture.
Cover and cook on low for 5-6 hours or until the potatoes are tender.
Sprinkle the shredded cheese over the casserole and cook covered for an additional 20 minutes or until the cheese is melted.
Garnish with chopped parsley before serving.
