Rub the butter into the flour until you have a breadcrumb texture. Add the water a little at a time to form a dough. Knead lightly then wrap in clingfilm and put in the fridge for 30 minutes.
Lightly flour a worktop and roll the pastry out so it's a little bigger than a 20cm tart tin. You need to have enough pastry to go up the edges with a little overhang. Prick the base all over with a fork then return the pastry to the fridge for another 30 minutes.
Preheat an oven to 190C. Remove the pastry from the fridge and place a sheet of baking paper onto the pastry; it needs to go up the sides too. Fill the pastry case with baking beans (see notes below). Put the tart case into the oven for 15 minutes to blind bake. Remove the case from the oven, carefully remove the baking beans and paper then return the case to the oven for another five minutes to crisp up.
The pastry case is then ready to use as below.
To make the quiche
While the pastry case cooks you can get the filling ready.
Steam the broccoli over a pan of boiling water until it's almost cooked, anywhere from two to five minutes depending on how big the florets are. Drain well and put to one side.
Add the spinach to a small pan on a medium heat and leave to wilt. Once the spinach has wilted, squeeze any excess water out by pressing the spinach against the side of the pan with a spoon. Put to one side.
In a small bowl, combine the eggs, double cream, a little salt and plenty of black pepper.
When the pastry case is ready remove it from the oven and reduce the oven temperature to 180C.
Put the smoked salmon, broccoli and spinach into the tart case. Pour over the egg mixture. Return the quiche to the oven for 25 minutes or until golden brown on top and there's still a slight wobble in the middle.
You can serve the quiche warm from the oven, leave it to cool, or cut into six wedges and freeze them individually.
Notes
If you don't have baking beans you can use rice or lentils instead. The idea is to weigh the pastry down so it doesn't rise up while blind baking.Blind baking helps to ensure you get nice crisp pastry.