Rub together the plain flour, pinch of salt and unsalted butter until you have a soft breadcrumb texture
Add enough cold water to make the breadcrumb mixture join together to make a firm dough and then rest this in the fridge for 30 minutes - I find it easier to form it into a relatively flat circle to be able to roll it out easier later, and then wrap it in clingfilm to protect it in the fridge
Grease and flour a tart case
Roll out the pastry on a lightly floured surface and line the tart case - you don't have to trim off the edges as the pastry will shrink away when cooking so this prevents that
Chill again in the fridge
Quiche
Preheat the oven to 190C (180C fan)
Remove the tart case from the fridge and line it with baking parchment and fill with baking beans or uncooked rice
Place on a baking tray and bake for 20 minutes, remove the baking parchment and beans, and bake for a further 5 minutes
Once cooked, leave to cool
Prep the leeks by pealing the outer layers, chop off the bottom root and the leaves so you're left with the solid bit in the middle and wash thoroughly.
Prep the mushrooms by washing and chopping into small slices
Using a knob of butter, cook them in a pan on a medium heat until the leeks and mushrooms have cooked through
Sprinkle cheese onto the base of the tart case - I use roughly 150-200g of it (depends how cheesy you like it)
Tear up pieces of the ham and place on top of the cheese so the base is covered in ham
Put the leek/mushroom mixture on top of the ham and spread it out evenly
Sprinkle the rest of the cheese on top - it'll make the quiche nice and brown once its cooked
In a jug or a bowl, mix the double cream and the eggs together and pour over the top of the quiche evenly
Place in the oven and cook for 20 minutes and check its progress. If it has browned nicely and has stopped wobbling so much it is ready, if not put it in for another 5 minutes.
ENJOY!
Notes
You can leave the meat out if you're a vegetarian, or swap it for a different meat if you prefer!
I often serve my quiche with a light salad, or if for dinner it would be some homemade potato wedges too!