This was inspired by one of my favorite basic quiche recipes. I would make the quiche with the chicken and Gruyere cheese. To me, the key to both the quiche and the frittata is the Gruyere. The distinctive, nutty flavor of the cheese makes these dishes special. Even a very good Swiss would not work as a substitute for me.
Chicken and mushroom frittata
3/4 cup cooked chicken breast, 1/4- to 1/2-inch pieces
1 cup sliced mushrooms
1/2 cup shredded Gruyere cheese plus a little more for the top
Melt a small amount of butter in the pan and cook the mushrooms for several minutes until they are just starting to get brown. Remove them from the pan.
Put the eggs into a good-sized mixing bowl and beat just to mix them up. Add a bit of oil to the pan if needed and let it get hot. Add a small amount of egg mixture to the pan to set the bottom of the frittata to prevent sticking. Turn the heat down to medium low. Mix the chicken, mushrooms, and Gruyere into the eggs and pour the mixture into the pan. Cook this for about 5 minutes to set the bottom and sides.
Preheat the broiler. When the 5 minutes cooking on the stove are up, sprinkle a bit more of the cheese on the top. Place the pan under the broiler, about 6 to 7 inches below. Cook until the top is set and just starts to brown. This is about 1–1/2 to 2 minutes for me, but watch closely.
Remove from the broiler, loosen up the sides with a spatula if necessary, and slide the frittata out onto the serving plate.