View the original recipe via:
Wash the leeks thoroughly, then slice in not too thick chunks. Heat up a knob of butter in a large pan and add in the sliced leeks. It's not necessary for the leeks to be browned, so make sure to not turn the heat up too much.
Cook until pretty much all of the moisture has disappeared from the pan, then the leeks will be nice and reasonably soft. In the meanwhile, preheat the oven to a temperature of 200 Degrees Celsius (390 Fahrenheit).
Grease the round cake tin with butter.
Cover the greased up cake tin with puff pastry and poke holes in the bottom using a fork. Mix eggs with milk and cream in a medium-sized bowl using a whisk. Season with grounded pepper, salt and a pinch of nutmeg.
Divide the soft leeks over the puff pastry and pour over the egg-cream mixture. Bake in the oven until golden-brown in about 20 - 25 minutes time.
The exact time depends on the type of oven and the type of puff pastry. Serve hot, preferably with a salad on the side. Enjoy your meal!