Sift the flour into a bowl, add the butter and rub between your fingertips until it resembles breadcrumbs.
Add water and mix with your hands until it comes together and forms a dough. Flatten the pastry into a round disc and then cover in cling-film and leave it to rest in the fridge.
Roll out the pastry on a lightly floured surface until it’s big enough fit over a 26cm tart tin, trim the pastry a little, but leave an overhang –the pastry will shrink a little, you can cut it when it’s cooked. Prick the pastry all over with a fork and place the pastry case in the fridge for at 20 minutes.
Heat oven to 200C/180C fan/gas 6, take the pastry case from the fridge, line it with baking parchment and fill it with baking beans, place the pastry in the oven and cook for 20 mins.
Remove the baking beans and paper from the pastry and cook for 5 mins more until pale golden. Turn down the oven to 180C/160C fan/ gas 4. Trim the edges of the pastry case with a vegetable peeler, until it is neat and there is no overhang.
If necessary shred the salmon and then lay it in the bottom of the pastry case. Whisk the eggs, milk and cream together and season well, then add in the chopped parsley.
Pour the mixture over the salmon and bake for 30-40 mins, or until set with a slight wobble in the centre.
I personally have always preferred quiche cold, but you can serve this warm from the oven or warm it yourself before serving.