FOR THE PASTRY
400g plain flour
60g cold butter, chopped
60ml extra virgin olive oil
110ml cold water
FOR THE FILLING
1kg potatoes, scrubbed (I prefer Nicola potatoes as they keep their texture and have a lovely sweet flavour)
extra virgin olive oil
2 leeks, white part only, finely sliced
2tsp each of oregano, thyme and sage (you could also use marjoram or rosemary in place of any of these)
1tbsp flat leaf parsley, chopped
1/2 tsp dried chilli flakes
250g mozzarella, roughly chopped
1 egg, lightly beaten
1. For the pastry, place the flour and butter in a large bowl. Rub the flour into the butter until the mixture resembles course breadcrumbs. Pour in the olive oil and add the cold water to the flour to form a soft but not stick dough. You may not need to use all of the water so be sure to add just a little at a time. Turn out onto a surface bringing the dough together and gently kneading until a smooth dough has formed. Wrap in cling film and leave to rest in the fridge for at least 30 minutes.
NB: The dough can also be made in food processor. Just be sure to blitz the flour and butter together first before adding the oil and water.
2. Preheat oven to 180C. For the filling, place the potatoes in a large pot and cover with cold water. Bring to the boil and cook until potatoes are just tender (approx 20 minutes, depending on size). Drain, leave to cool and roughly slice.
3. For the leeks, place a large pan over a medium heat and drizzle in a little olive oil and add a knob of butter. Add the leeks and gently sauté until softened and beginning to caramelise (approx 10-15 minutes). Stir through the herbs, chilli flakes and parsley.
4. In a large bowl, place the potatoes, leek mixture and mozzarella and gently stir until all the potatoes are coated. Season to taste.
5. Remove the pastry from the fridge and roll out half of the dough to 1cm thick to form an approximate circle shape. Place on a lined tray and arrange the potato mixture on the pastry, leaving a small border. Roll out the remaining dough a little thinner but to the same shape as the base. Lay the piece of pastry over the filling and base and seal the two edges in a rough crimping action.
6. Pierce a hole in the top of the pastry to allow steam to escape and brush pastry with the beaten egg. Bake in the preheated oven until pastry is crisp and golden (approx. 30 minutes). Serve hot.
Source : Julia Ostro