Pie Crust:

1. Place the butter, flour, and salt in the food processor, and pulse lightly just until the mixture resembles wet sand.
2. Add the water, 1 tablespoon at a time, pulsing after each addition of water. Keep adding water until the dough just begins to gather into larger clumps.
3. Shape the dough into a disc, cover in parchment paper/aluminum foil or place in a plastic ziptop bag and refrigerate at least half an hour or overnight. You can also make pie dough in advance and freeze it up to 6 months.
4. Take the dough out of the refrigerator and let it stand at room temperature for 5-10 minutes.
5. On a floured surface, roll the pie crust out into a 12-14 inch circle if you’re using a deep dish pie pan and 10-12 inch circle. Ease it gently into a deep dish pie plate.
6. Crimp the edges of the pie to make a pretty edge all the way around. Use a fork to make perforations all over the bottom of the pie crust. Place the pie shell in the freezer for about 30 minutes.
7. Meanwhile, preheat the oven to 375 degrees Fahrenheit. Cover the entire pie with parchment paper or aluminum foil and distribute pie weights or dry beans into the center of the pie.
8. Bake in the preheated oven for about 15 minutes. Remove the parchment paper with the weights and continue baking the pie shell for another 10-15 minutes.

Pie Filling:

1. While the pie crust is chilling and then baking, prepare the filling.
2. Cook the bacon over medium heat on the stovetop (or in the oven and then crumble into small pieces). Set the bacon aside and drain on a paper towel. Get rid of most of the grease except for about 1/2 Tablespoon and add the onion, cooking over medium heat until the onions are tender and slightly golden, 3-5 minutes. Add the onions to the bacon on the paper towel to drain and cool slightly.
3. Place the bacon, onions and grated cheese on the bottom of the partially baked pie crust. 
4. In a large bowl, whisk the eggs together until combined. Add the milk, heavy cream, salt and ground black pepper and mix to combine. Pour the egg custard over the bacon, onion and cheese.
5. Bake in the preheated oven (375 degrees Fahrenheit) for about 35 minutes, then cover the edges of the pie crust with aluminum foil so that they don’t get too brown.
6. Continue baking for another 20-30 minutes, until the center of the quiche seems set. You can check for doneness by inserting a knife blade into the quiche and it should come out clean. Remove the quiche from the oven and cool on a wire rack for 5-10 minutes before serving.