Heat oven to 375°F. Spray shallow 2-quart casserole with cooking spray. In 12-inch nonstick skillet, cook beef, onion, carrots and garlic over medium-high heat 5 to 7 minutes, stirring occasionally, until beef is thoroughly cooked; drain. Stir in broth, tomato paste, Worcestershire sauce, 3/4 teaspoon of the salt and the thyme. Heat to boiling; reduce heat. Cover; simmer 10 minutes.