1In 4-quart Dutch oven, cook beef over medium heat until brown on all sides. Reduce heat to low.
2Sprinkle beef with salt and pepper. Spread horseradish over all sides of beef. Add 1 cup water to Dutch oven. Heat to boiling; reduce heat. Cover and simmer 2 hours 30 minutes.
3Add potatoes, carrots and onions to Dutch oven. Cover and simmer about 1 hour or until beef and vegetables are tender.
4Remove beef and vegetables to warm platter; keep warm. Skim excess fat from broth in Dutch oven. Add enough water to broth to measure 2 cups. In tightly covered container, shake 1/2 cup cold water and the flour; gradually stir into broth. Heat to boiling, stirring constantly. Boil and stir 1 minute. Serve gravy with beef and vegetables.