For the puff pastry:
220g plain flour
100g butter – cold, but not fridge cold – cut into small pieces
A pinch of salt
A little cold water
A tablespoon of dried oregano
75g strong cheddar, grated
For the cheese sauce:
40g plain flour
500ml milk or 250 ml of milk and 250ml stock vegetable or chicken
75g strong cheddar (or any cheese)
For the filling:
4 leeks, thickly sliced
100g frozen peas
1/4 a left-over roast chicken, shredded or cubed
A large glug of Pernod
Salt and pepper fresh
Rosemary and thyme
To make the pastry, sieve the flour into a large bowl, add the butter and rub it into the flour, raising your hands high as you do to allow plenty of air to get into the flour. This rubbing process will not be easy as the butter is cold, but you're not after a fine breadcrumb, you want some large pieces of butter in there.
Add the oregano, cheese and salt and mix together, then add a few drops of water and using one hand shaped like a claw, begin to stir the flour and butter together, it should start to come together into a dough but you'll need to dribble in a little more water for it to fully come together.
Once the dough is formed, tip it out onto some cling film, pat it out into a flat disk shape, then wrap it up and pop it in the fridge for 15 mins.
When cold, take it out of the fridge and, still on the cling film, roll it out to double its size. Then you want to envelope-fold the dough, which means folding the top over and the bottom up to create an envelope. Then roll flat, turn by 90 degrees and envelope-fold again.
Wrap it back up and refrigerate for a further 30 mins. It should now be ready to use.
Pre-heat the oven to 190C (170C fan).
To make the pie, place your leeks into your pie dish, drizzle over a little olive oil, season well with salt and pepper and sprinkle over plenty of fresh herbs - cover in foil and roast in the oven for 20 mins. Then remove from the oven, un-cover, pour over the Pernod and stir in the peas, re-cover and pop back in the oven for a further 5mins or until the vegetables are al-dente. Remove from the oven and set aside.
Make the cheese sauce by melting the butter gently in a small pan.
Once melted, remove from the heat and stir in the flour to make a smooth but thick paste. Then add a dash of the milk/stock and again stir into a paste. Place the pan back on a gentle heat and slowly add a little milk at a time, stirring well between additions. If it looks like it may become lumpy take the pan off the heat and stir until smooth. Continue this way until all the milk is gone and you have a nicely thick sauce – let it bubble away very gently on the heat for 10 minutes, stirring regularly. Add the cheese and stir until melted.
Pour the cheese sauce over the vegetables in the pie dish, add the chicken and set aside to cool for at least 15 minutes before you attempt the lattice pastry crust
Generously flour your work surface and roll out the pastry into a large oblong and then cut it into six long strips and eight shorter strips.
Lay the long strips lengthways along pie dish, with gaps in between then take one shorter strip and, starting from one edge of the pie dish, weave it over and under each long strip. Continue this way until all your pastry strips are woven. I like it looking quite rough and ready but feel free to trim to make it nice and neat.
Brush with a little beaten egg before baking for 25 mins or until thepastry is golden and puffy.
Serve with fresh green veg, like kale or broccoli.