You can do virtually anything with this recipe. Different veggies, different types of cheese, different types of meat. I do not like mushrooms, so I substituted green peppers, and I used Mozzerella cheese, which is what I had on hand.
I agree with many other posters, that 1/2 cup of milk works perfectly! 1 cup would have been too much I think.
This morning I toasted an english muffin and then put my reheated quiche in the middle and smooshed it down. It was an instant breakfast sandwhich, and way tastier than the fast food kind! The flavors in this recipe are great, and these make perfect and convenient breakfasts and snacks. I think I will be making these every weekend!