Cook the Bacon: In a large skillet over medium-high heat, cook the bacon until crispy. Remove with a slotted spoon and set aside. Drain all but 1 tablespoon of the grease.
Brown the Kielbasa: Add sliced kielbasa to the skillet in a single layer. Cook for 3 to 4 minutes, flipping once, until browned on both sides. Remove and set aside.
Cook the Ground Beef & Vegetables: Add ground beef, onion, bell pepper, and garlic to the skillet. Cook, stirring occasionally, until beef is browned and vegetables are tender.
Thicken the Mixture: Sprinkle the flour over the beef mixture and stir well. Cook for 1 to 2 minutes, just until the raw flour taste is gone.
Assemble the Stew: Transfer the beef mixture, bacon, kielbasa, and all remaining ingredients to a 6-quart slow cooker. Stir to combine.
Cook: Cover and cook on high for 4 hours or low for 6 to 8 hours, until the potatoes are tender.
Serve: Ladle into bowls and serve warm!
