01 -
Preheat oven to 350°F.
02 -
Sprinkle Parmesan cheese in the bottom of a 9-inch pie pan. Bake for 5 minutes.
03 -
In a large mixing bowl, stir together Colby cheese, Swiss cheese, mozzarella cheese, lightly beaten eggs, milk, and mayonnaise. Mix well.
04 -
Add chopped onion, flour, spinach, and bacon to the cheese mixture. Stir well.
05 -
Pour the prepared mixture over the Parmesan cheese base layer in the pie pan. Bake for 55 minutes to 1 hour, or until the center is set.
06 -
Allow the quiche to rest for 10 minutes before slicing and serving.