Method:

• In medium bowl, combine eggs, milk, chives, marjoram, salt and pepper; mix well. Set aside.
• Heat 1 tablespoon oil in large nonstick skillet over medium-high heat until hot. Add onion, zucchini and garlic; cook and stir 1 minute. Reduce heat to medium. Add broccoli, corn and 1/4 cup water; cover and cook 4 to 6 minutes or until vegetables are crisp-tender, stirring occasionally. Remove vegetables from skillet.
• Add 2 teaspoons oil to skillet. Return vegetables to skillet; pour egg mixture over vegetables. Cover loosely; cook over medium heat for 10 to 15 minutes or until center is set, lifting edges occasionally to allow uncooked egg mixture to flow to bottom of skillet.
• Sprinkle frittata with cheese; arrange tomato slices on top. Cover; cook 1 to 2 minutes or until cheese is melted. If desired, garnish with additional chives or sprigs of marjoram. To serve, cut into wedges.