Make the quiche crust. Add the Miracle Mix, xanthan gum, and sea salt to a food processor. Pulse to combine.

Add the cold butter and cream cheese. Pulse for 3 seconds. Add one egg and vinegar and pulse just until it forms a dough ball (do not over-process).

Place dough on a piece of cling wrap and wrap tightly. Refrigerate.

Preheat oven to 400 F. Dice the bacon and thinly slice the onion. Grease a 9" tart pan with a removeable bottom (a 9" pie pan will also work in a pinch).

Add the bacon to a safe skillet and cook over medium heat, stirring just until crisp. Scoop out the bacon pieces and reserve. Add the onion to the pan with the bacon grease and cook, stirring for 4-5 minutes to golden.

Remove crust from refrigerator. Roll dough out between parchment paper or cling wrap. Place tart pan over the rolled-out dough. Invert the pan and press dough into the pan evenly. Transfer back to the refrigerator.

Get the filling ready. Grate the cheese and set aside. Add the remaining four eggs, sour cream and nutmeg to a large bowl. Whisk to combine.

Remove crust from the oven and prick the bottom with a fork. Transfer to the oven and par-bake 15 minutes.

Top par-baked crust with half the cheese and the bacon and onions. Pour the egg mixture over. Scatter remaining cheese on top.

Transfer to the oven and bake 30 minutes, or until a knife inserted two inches from the center comes out clean.

Let cool 10 minutes, then unmold and serve.