Mini Spinach Feta Frittatas

Preheat oven to 350ºF. Liberally grease a muffin pan with cooking spray.

In a large skillet, heat butter. Add onions and cook until soft, about 2 minutes. Add in mushrooms, pepper, summer squash and spinach; cook another 5 minutes. Remove from heat.

In a small bowl, beat eggs, salt and pepper.

Scoop vegetable mixture into the muffin cavities, filling about half-full. Pour egg mixture over each one, being careful not to overflow the cups. Sprinkle feta cheese over eggs. Sprinkle with additional salt and pepper to taste.

Bake for 15–18 minutes, or until eggs are fully cooked. Serve warm and enjoy!