HEAT oil in 5-quart Dutch oven over medium heat. Add onions; cook, stirring occasionally, until lightly browned. Stir in garlic; cook 1 minute. Add beef, tomatoes, beef broth, Worcestershire sauce, thyme, salt and pepper. Bring to a boil. Reduce heat and cover. SIMMER 1 hour. Add potatoes; cook 15 minutes. Stir in vegetables and simmer 15 minutes longer. COMBINE water and corn starch in small bowl until blended. Whisk into meat mixture. Stirring constantly over medium heat, bring to boil. Boil 1 minute. LADLE into serving bowls.