If using bamboo skewers, soak skewers in water. In medium bowl, toss vegetable pieces with 2 tablespoons dressing; set aside. In large bowl, combine ground beef, egg, oats, milk, onion, garlic, thyme, salt and pepper; mix lightly but thoroughly. Shape mixture into 20 meatballs, about 1-1/2 inches in diameter. Alternately thread meatballs and vegetables onto eight 12-inch bamboo or metal skewers. Arrange kabobs on broiler pan that has been sprayed with nonstick cooking spray. Drizzle with any dressing remaining in medium bowl. Broil 3 to 4 inches from heat, until meatballs are cooked through (160ºF) and vegetables are tender, about 10 minutes, turning once and brushing with remaining 2 tablespoons dressing. Serve kabobs sprinkled with cheese, if desired.