In a large bowl, mix the flour and salt together.
Add the cold butter cubes to the flour and gently rub in using the tips of your fingers, until the texture resembles breadcrumbs.
In a small bowl or mug, beat the egg yolk and cold water together with a fork.
Add the wet ingredients to the flour and using a blunt knife / butter knife, stir them together. You may need to use your hands at the end to lightly bring the pastry together.
Form the pastry into a disc and wrap in cling film. Place in the fridge to rest for at least 30 minutes.
Preheat the oven to 180˚C fan / 200˚C / 356˚F convection / 392˚F
Lightly dust the work surface and rolling pin with flour. Unwrap the disc of dough and gently roll out to a thickness of 3-5mm (0.10-0.20 inch), rotating 90 degrees every few rolls to ensure even thickness and prevent the dough from sticking to your surface.
Place the rolled out pastry into your quiche tin or pie dish, gently pressing the pastry down with your fingers into the edges of the tin.
Cut away any pastry overhanging the edges of the tin / dish with a sharp knife and prick the base with a fork. Line the pastry with a sheet of baking paper and fill with baking beans. Place in the preheated oven for 15 minutes.
While the pastry cooks, fry the bacon in a non stick pan over a medium heat until golden (you shouldn’t need any oil). Remove to a plate lined with kitchen paper towel and set aside to cool.
Take the pastry of the oven and remove the baking paper and baking beans. Using a pastry brush, brush a little of the beaten egg all over the base and sides of the pastry case, then return to the oven for 5-7 minutes until lightly golden.
Whisk the beaten eggs with the creme fraiche, ground nutmeg, salt and black pepper.
Scatter the crispy bacon over the base of the pastry in an even layer, then carefully pour over the egg / creme fraiche mixture.
Bake in the oven for 35-40 minutes until golden and set (it should still jiggle slightly in the middle)
Stand for 10 minutes before serving.
Store any leftovers in the fridge for up to 3 days.