Trim fat from beef. Cut beef into 1-inch cubes. In a Dutch oven heat olive oil over medium-high heat. Cook and stir beef and onion in hot oil until beef is browned. Stir in the water, beef broth, undrained tomatoes, Italian seasoning, pepper, and bay leaf. Bring to boiling; reduce heat. Simmer, covered, for 40 minutes.
Stir in the turnips, potatoes, and carrots. Simmer, covered, for 15 minutes. Stir in the noodles. Simmer, uncovered, about 10 minutes more or until noodles and vegetables are tender. Remove bay leaf. If desired, stir in oregano or thyme.