1. To make the dough, put the flour and salt into a food processor with the blade attachment. Add in the cubed cold butter and pulse it 4 to 5 seconds at a time until the flour resembles breadcrumbs. Do not leave large chunks of butter in the flour.
2. Add in the first 2 tbsp. of ice water and pulse it again. Add the remaining 2 tbsp. of ice water one at a time until the dough just comes together when you pinch it. Add extra ice water if your dough looks too dry.
3. Do not pulse it until a dough ball is formed. That means you have over worked the dough.
4. Pour out the contents of the food processor onto a clean work surface and gently gather the dough together until it forms a ball. Do not knead it.
5. Wrap it in cling film and let it rest in the fridge for half an hour.
6. Now to make the filling. Sauté the chopped bacon with butter until slightly crispy. Drain the crispy bacon on paper towels and sauté the diced onion with the remaining fat in the pan.
7. Do not colour the onions, you want it soft and translucent. Set it aside.
8. Combine the cream, milk and black pepper together. Set it aside
9. Remove the pastry from the fridge and split the dough into 2 and reserve the second ball of dough for a second quiche or freeze it for another day.
11. Roll out 1 dough ball into 3mm thickness on a lightly floured surface.
12. Gently transfer the rolled out pastry onto a pie dish. Prick it with a fork a few times on the base and blind bake it at 200 degrees for 7 minutes.
13. Let the pre-baked quiche base cool for 10 minutes.
14. Put half of the onions onto the base, followed by a scattering of half of the bacon. Gently pour in half of the egg mixture and scatter half of the grated cheese.
15. Layer the remaining half of the onions, bacon and final pouring of the egg mixture and cheese.
16. Bake it in the oven at 170 degrees for 40 to 45 minutes. Do not bake it until it is completely set. Remove it from the oven when where is still a slight jiggle in the center.
17. Let the quiche cool for half hour before cutting it.
Note : Blind baking is to pre-bake the pastry base before adding any filling to it. This is to avoid soggy uncooked base.