Preheat the oven to 200ºC.
Unroll the pastry and lift into a quiche tin.
Prick the base all over with a fork.
Place a sheet of baking parchment on top of the pastry.
Fill with baking beans.
Place in the oven and bake for 15 minutes.
Remove from the oven and remove the beans.
In a bowl add the eggs, crème fraîche, grated Cheddar and mustard.
Whisk together, then pour half into the pastry case.
Add the spring onions then pour over the rest of the mixture.
Scatter over the parsley and remaining spring onions.
Bake for 20-25 minutes, until set but still a little wobbly.
Leave the tart to stand for 5 minutes, then slice and munch.