1. Preheat your oven to 400 degrees Fahrenheit. Line a tart pan or a pie pan with the crust, and bake for 12 minutes.
2. Melt the butter in a skillet over medium/high heat. Sauté the onion until soft and translucent.
3. Remove the skillet from the heat and stir in the chopped spinach until completely combined. Spread the
spinach/onion mixture onto the bottom of the pie crust.
4. In a blender or food processor, combine the cheese, eggs & yolks, cream, mustard and salt and pepper. Pour over
the spinach/onion and return to the oven for 22-26 minutes, until the top is golden. Turn off the heat and leave in
the oven for an additional 5 minutes.
To freeze: cut the pie into slices and freeze individually, wrapped in parchment and placed into a freezer bag. To serve,
defrost completely and reheat in your microwave.