Preheat your oven to 180°c. Grease a large pie dish, and spread out the sheet of pastry, and shape until it covers the base and sides of the dish.
Bake the pastry for 10 minutes, while your prepare the mixture.
Mix together remaining ingredients. Save some cheese to sprinkle on top. When the pastry has just started to brown, pull out of the oven, pour the mixture inside, sprinkle some extra cheese on top.
Place the dish back in the oven until the egg has set, about another 30 minutes. Enjoy!