01 - Preheat oven to 375°F.
02 - Whisk together eggs, egg whites, low-fat milk, Parmesan, ricotta, salt, and pepper in a large bowl until well combined and frothy.
03 - Heat olive oil in a 10-inch oven-safe nonstick skillet over medium heat.
04 - Add bell pepper and zucchini; sauté for 3-4 minutes until beginning to soften.
05 - Add spinach, cherry tomatoes, and green onions; cook for another 2-3 minutes, stirring occasionally, until spinach is wilted.
06 - Pour the egg mixture evenly over the vegetables in the skillet. Gently stir to distribute vegetables evenly.
07 - Reduce heat to low and cook without stirring for 2-3 minutes until the edges set.
08 - Transfer skillet to preheated oven and bake for 15-18 minutes, or until the center is just set and the top is slightly golden.
09 - Remove from oven and let stand for 5 minutes. Garnish with chopped parsley.
10 - Slice into wedges and serve warm or at room temperature.