Preheat oven to 400. Remove Pie crust from freezer and let it thaw enough that you can easily prick it with a fork. Prick bottom and sides with a fork. Put a piece of parchment over the pie and put pie weights over the parchment. If you don’t have pie weights you can use dry beans. Bake until it turns a light golden brown ( about 10 mins). Set aside to cool.
Cook Bacon until crispy. Pat bacon dry and chop into small pieces. Set aside.
Dice Onions and cook in bacon grease until it is translucent or a little golden brown. Pat dry until all grease is absorbed. Set aside.
Shred Gruyere cheese. Set Aside
Combine Bacon pieces, cooked onions and Gruyere cheese, salt and pepper. Put mixture into the baked pie crust.
In a separate bowl, whisk heavy cream and eggs together. Then pour mixture into pie crust over the other ingredients. Sprinkle some extra cheese on top.
Place pie on a baking sheet. Bake at 325 degrees for about 45-55 min or until filling is set and the top is a golden brown.