1. Preheat oven to 375 degrees F and remove pie crust from fridge.
2. Whisk the eggs, heavy cream, salt, and pepper together in a large bowl.
3. Add the cheeses and onions to the egg mixture and stir until fully combined.
4. Roll out pie crust and press into a 9 inch pie dish. Crimp edges with a fork if desired.
5. Pour the egg mixture into the prepared pie crust and bake for 38-40 minutes or until quiche is fully set in the middle.
6. Let cool for 8-10 minutes before serving. Enjoy warm or room temperature!