Preheat the oven to 180°C.
Peel then slice the potatoes on a mandolin.
Finely slice the onions and leeks.
Melt the butter in a pan, add the onion and sweat these for 2-3 minutes without browning.
Add in the leeks and cook together until softened.
Add the sliced potato and cook for 5-6 minutes. Season and leave to cool.
Roll out two thirds of the puff pastry and line a 20cm dish. Roll out the remaining pastry to make a lid and rest in the fridge for 30 minutes.
Mix the parsley with the cooled potato and leek mixture and spoon into the pastry case.
Brush the edges with the beaten egg and cover with puff pastry.
Press the edges together, make a small hole in the centre and brush the top with the rest of the beaten egg.
Pop it into the oven for about 45 minutes to one hour, covering if it browns too much.
Once cooked, leave to rest for half an hour before pouring the boiled cream into the pie through the hole in the centre.
Leave it to rest for half an hour and serve at room temperature.
Serves: 6
Preparation: 30 mins
Cooking: 45 mins
750g Albert Bartlett Original Rooster Potatoes
300g leeks (well washed)
1 onion
50g butter
300g puff pastry
4 tbsp flat parsley (chopped)
1 egg
100ml boiled double cream