In a dutch oven or a large saucepan, combine ground beef, salt and pepper: cook over medium high heat until beef is browned and thoroughly cooked. Drained.
Add carrots, potatoes, onions and broth. Bring to a boil. Reduce heat: cover and simmer 15 to 20 minutes or until vegetables are almost tender.
Stir in zucchini, tomatoes, mushrooms, thyme and worcestershire sauce. Cook 5 to 10 minutes or until zucchini is tender
In a small jar with a tight fitting lid combine water and flour: Shake well to blend. Gradually add to stew, stirring constantly: cook and stir until bubbly and thickened.
