- 1 1/2 teaspoons olive oil
- 1 medium-size red onion, chopped
- 1 red bell pepper, coarsely chopped
- 1 medium zucchini, chopped
- 2 cups (packed) spinach leaves, torn into 1-inch pieces
- 3 large eggs
- 6 large egg whites
- 1/2 teaspoon salt
- 1/4 teaspoon ground black pepper
- 1 ounce shaved Asiago cheese
- 1 cup chopped tomatoes
- 1 tablespoon chopped fresh basil
- Preheat broiler. Heat olive oil in 10-inch-diameter nonstick skillet over medium-high heat. Add onion and bell pepper; sauté until golden, about 8 minutes. Add zucchini; sauté until tender, about 5 minutes. Add spinach; stir until wilted, about 1 minute. Season with salt and pepper.
- Whisk eggs, egg whites, salt and pepper in medium bowl to blend. Pour egg mixture over hot vegetables in skillet; stir gently to combine. Reduce heat to medium-low. Cook without stirring until eggs are set on bottom, about 5 minutes.
- Sprinkle cheese over frittata. Broil until cheese melts, about 2 minutes. Sprinkle with tomatoes and basil.