Preheat broiler.

Heat olive oil in 10-inch-diameter safe nonstick skillet over medium-high heat.

Add onion and bell pepper; saute until golden, about 8 minutes.

Add zucchini; saute until tender, about 5 minutes.

Add spinach; stir until wilted, about 1 minute.

Whisk eggs, egg whites, and pepper in medium bowl to blend.

Pour egg mixture over hot vegetables in skillet; stirring gently to combine. Reduce heat to medium-low. Cook without stirring until eggs are set on bottom, about 5 minutes.

Sprinkle mozzarella over egg mixture and then place under broiler. Broil until the cheese melts, about 2 minutes.

Top with tomatoes and basil, and salt and pepper.

Serve.