Heat oven to 350°F; coat a 9-inch deep dish pie plate with cooking spray.
Sauté mushrooms and onion in olive oil in a large skillet over medium high heat for 5 minutes or until mushrooms are tender. Add the spinach; cook for 2 minutes or until the spinach is wilted. Transfer to prepared pie plate.
In a bowl, whisk the eggs, milk, salt and pepper until eggs are light and frothy. Add the cheese and mix to combine. Pour egg mixture over the spinach mixture.
Bake at 350°F for 40 to 45 minutes, or until eggs are set and a thermometer inserted into the center reads 165°F. Let cool 10 minutes before slicing and serving.
Serve with Spinach Arugula salad.
Dressing Instructions:
To make the dressing, whisk all ingredients in a small bowl.
Place the Fresh Express® Spinach & Arugula in a large bowl; drizzle with dressing when ready to serve.