Put the potatoes and carrots in a large slow cooker; top with the onion wedges then the beef. Combine the ketchup, 1/4 cup water, vinegar, paprika, chili powder, mustard, garlic powder, Worcestershire sauce, and salt. Pour over the beef. Cover and cook on LOW for 8 to 10 hours, or HIGH for 4 to 5
southernfood.about.com