Spinach Feta Frittata

Ingredients

For 4 servings

• 4 large whole eggs
• 1 cup egg whites
• 1 teaspoon olive oil
• 1/2 cup red onion (finely chopped)
• 3 medium scallions (chopped, plus more for topping)
• 1 1/2 cups fresh chopped spinach
• 2 ounces crumbled feta (plus optional more for topping)
• 2 tablespoons Parmigiano-Reggiano (grated)
• 1/2 teaspoon kosher salt ( and freshly ground pepper)
• diced grape or cherry tomatoes (optional for topping)