An asparagus and mushroom frittata is a quick and easy dish to prepare for breakfast, brunch, or dinner.
Set oven to 375 degrees Fahrenheit (190 degrees C).
Cooking spray should be used to coat an 8-inch square baking dish.
In a skillet, heat the olive oil over medium heat.
Cook the onion, red bell pepper, mushrooms, and asparagus, stirring frequently, for 5 to 10 minutes, or until the onion is translucent.
In the baking dish that has been prepared, spread the onion mixture.
When smooth, combine egg whites, skim milk, and a bowl; pour over onion mixture.
Add Cheddar cheese on top of the egg mixture.
Until the frittata is set in the middle and a fork inserted in the center comes out clean, bake in the preheated oven.