Aged Cheese Quiche (västerbottenostpaj)

Preheat your oven to 190ºC.
Make the shortcrust pastry by blitzing the flour, butter, egg yolk and salt in a food processor until well combined.
Press the dough together and leave covered in the fridge for at least 30 minutes.
Make the quiche filling by cooking the onion in the butter over a low heat until translucent, and leave to cool.
Whisk together the eggs, cheese, cream, paprika and softened onion.
Remove the pastry from the fridge and dust a benchtop with plain flour. Roll the dough into a thin sheet, no more than 2 cm thick.
Line a shallow quiche or pie dish with the pastry and blind bake the case for 10 minutes, or until lightly golden.
Pour the cheese mixture into the pastry case and return to the oven for 20 minutes, or until golden on top.
Remove from the quiche from the oven. To allow the filling to set, cool the quiche for 10 minutes. Serve cold.