You can use any combination of ingredients you like including ham & broccoli, spinach & feta or sausage, peppers and mushrooms.  We often use leftovers from the weekend to put in them and change up the cheeses depending on what we have on hand. I use store bought egg whites in a container, I like how it makes the texture a little bit lighter.  If you’d prefer to use whole eggs, replace the 1  cup of egg whites in the recipe and use 12 eggs total. (1 egg per cup).   Can serve on English muffin and make an egg sandwich