"Preheat oven to 350 degrees F. Grease a standard non stick 12-slot muffin pan with cooking spray and set aside. Heat a large non stick skillet over medium heat. Once hot, add in oil, red pepper, green pepper, and onion.
Saute 5-7 minutes, or until peppers are tender.
Add in spinach and mushrooms and cook for an additional 2 minutes. In the last 30 seconds, add in minced garlic.
Season with salt and remove from heat.
Crack eggs/egg whites into a large 4 cup measuring cup and whisk together. Stir in cooked veggies. Pour the egg/veggie mixture evenly into the prepared muffin pan. Bake for 15-20 minutes, or until the tops are firm to the touch and eggs are cooked.
Cool slightly and serve immediately! Leftovers can be stored in an airtight container in the fridge for about 4 days. These may also be frozen. To reheat, pop them in the microwave until warm."