In a large soup pot over medium heat, brown the ground beef with onion for about 5 minutes, or until meat is no longer pink; stir to crumble meat as you cook (add oil if needed to keep meat from sticking).
Add in tomatoes, stock, tomato juice, thyme, salt, pepper, Worcestershire sauce, and Tabasco sauce.
Bring to a boil.
Lower heat to medium-low; simmer, uncovered, for 30 minutes.
Increase heat to med-high; add in vegetables and tortellini; cook, uncovered for about 10 minutes or until vegetables/tortellini are tender.
Ladle into individual soup bowls; sprinkle cheese on top.