Combine beef, potatoes, onion, peppers, and garlic in a large bowl. In a small bowl, mix together the flour, chili powder, cumin, and salt. Toss the beef mixture with the flour mixture until evenly coated. Place the mixture into a slow cooker, and pour in enough beef broth to barely cover the meat. If you don't have quite enough, you can fill the rest of the way with water.
Cook on Low until the beef is tender, 6 to 8 hours.
