Heat oven to 350°F. In 12-inch ovenproof nonstick skillet, heat broth to boiling over high heat. Stir in bulgur; reduce heat to low. Top bulgur evenly with zucchini, mushrooms, bell pepper and onion. Sprinkle with oregano and basil. Cover; cook 12 minutes. Fluff bulgur with spatula, mixing with vegetables.
Meanwhile, in medium bowl, beat eggs, milk, salt and pepper with wire whisk until well blended. Pour egg mixture evenly over bulgur mixture. Increase heat to medium-low. Cover; cook 5 minutes.
Remove cover; sprinkle with cheese. Bake uncovered 5 to 7 minutes or until sharp knife inserted in center of egg mixture comes out clean.
Meanwhile, in medium microwavable bowl, mix tomatoes and dressing. Microwave uncovered on High 30 seconds to blend flavors.
Cut frittata into wedges (bulgur will form a “crust” on the bottom; use spatula to lift wedge out of skillet). Top with tomato mixture.