For the quiche mix flour, butter, egg, milk and salt with your hands for about 10 minutes.
Wrap in cling wrap and refrigerate for 1 hour.
If you buy really thick asparagus then you might want to peel the outside woody part with a potato peeler. Snap off the tough base of each spear and chop into small pieces. Boil with a pinch of sugar and half a lemon for approximately 10 minutes. Drain and set aside.
Wash the mushrooms and cut them into pieces.
In a pie plate, place the pie pastry and spread the asparagus and mushrooms on top.
In a medium bowl, whisk together eggs, cream, pepper and salt, stir in grated cheese. Pour mixture over the asparagus and mushrooms.
Bake for 20 to 30 minutes until filling is just set.