In a large skillet, cook beef and onion over medium heat until meat is no longer pink; drain. Add the tomato juice, carrot and potato. Stir in seasonings. Bring to a boil. Reduce heat; cover and simmer for 10-15 minutes or until vegetables are tender.
Meanwhile, in a large saucepan, melt butter. Stir in flour until smooth; gradually add milk. Bring to a boil; cook and stir for 1-2 minutes or until thickened. Stir in vegetable mixture; heat through.