Preheat the oven to 400 degrees.

Brown the sausage in a medium size skillet. As it gets closer to being browned, add the entire bag of spinach.

Drain any excess moisture.

Stir in the pesto.

Whisk together the egg whites and add salt and pepper.

Spray a 12-cup muffin tin with cooking spray.

Divide the sausage/spinach pesto mixture evenly in the muffin cups.

Pour the egg whites into the cups until each one is about 3/4 full.

Bake for 20 minutes or until the cups are fully cooked in the middle.