Preheat oven to 375 degrees.

Combine butter, flour, and salt. Using a pastry blender cut in the butter until very crumbly. Add chilled water a tablespoon at a time mixing with a fork until the dough pulls together.  Form into a disk, wrap in plastic, and chill for at least 2 hours up to overnight.

Gently roll the pie dough out to a 12 inch circle on a lightly floured surface.  Fold the piecrust or roll it around your rolling pin to move it to a 9 inch deep dish pie plate.  Gently tuck it into the pie pan, trim the edge about an an inch over the side, tuck it in along the edge and flute it.  Line the pie crust with aluminum foil and fill with pie weights, rice, beans, or sugar.  Bake in the preheated oven for about 15 minutes.  Remove from the oven and carefully remove the weights and foil.

Reduce oven temperature to 350 degrees.

Heat olive oil in a large skillet over medium heat.  Add the onion and cook until soft; 5-7 minutes.  Add the spinach and cook until wilted.  Add the garlic, salt, and pepper; cook for 1 minute stirring constantly.  Add the mixture to the piecrust and top with the chopped bacon.

Add the shredded Swiss and cheddar cheese. Whisk the eggs and whipping cream together.  Pour over the spinach and bacon.  Bake for 55-60 minutes or until a knife inserted in the center come out clean. The center should still be slightly jiggly.  Let the quiche cool for 15-20 minutes before slicing.