Fry onions in the butter in a over medium-low heat for at approximately 15 to 20 minutes; stir occasionally,until the onions are deep golden brown.

Set aside to cool.

Fry the bacon until chewy. Chop into large bite-sized pieces and also set aside to cool.

Preheat the oven to 400.

Roll out the pie crust and press it into a large fluted deep tart pan or any kind of deep dish pie pan.

Whip the eggs, cream, salt and pepper in a large bowl.

Mix in the onions, bacon, and cheese. Pour the mixture into the pie crust.

Place pan on a rimmed baking sheet and cover lightly with aluminum foil; bake it for approximately 40 to 45 minutes.

Remove the foil and continue baking for 10 to 15 minutes.

Remove from the oven and allow to sit for about 10 minutes.