Cut the onion into fine slices and sauté in a pan with a little bit of butter. Place the spinach in a saucepan filled with 3 inches of water and heat until boiling for about 1minute. (Spinach must be well cooked but still green.) When done, drain well, chop and then sauté in the saucepan with the onions.  Set aside to cool for a few minutes. In a side bowl, mix two eggs, the Parmesan cheese, and the whipping cream, then incorporate in the same bowl with the spinach and onions. Salt and pepper to taste. Mix well. Cover a 9 1/2-inch pie plate with the pie crust (spray some cooking spray or butter to prevent sticking) and incorporate the mix. Cook in the oven at 400 degrees for about 10 minutes or until golden brown. 
Enjoy!