In a large pot over medium heat, cook beef, onion and potatoes, covered, until beef is no longer pink and potatoes are tender, 10 to 15 minutes.
Meanwhile, place carrots and 1/2 cup water in a microwave safe bowl and microwave on high 5 minutes, until tender.
Drain beef mixture and return to pot with carrots, corn, green beans, juice cocktail, water, salt and pepper. Simmer over low heat 30 minutes, until flavors are well blended and soup is hot.
