Cheese, potato, swede and chorizo pie

Method

1. Begin by making the pastry. Put the flour, fennel seeds, nigella seeds and a big pinch of salt in a mixing bowl, then rub in the butter until it resembles coarse breadcrumbs (you can also do this in a large food processor or the bowl of a stand mixer with a beater attachment). Mix in most of the egg (reserving some to brush the pastry later), then add cold water 1 tbsp at a time (no more than 3 tbsp) until it comes together into a stiff dough. Wrap and chill for at least 30 minutes.
2. While the pastry rests, make the filling. Melt the 50g butter in a medium pan over a low-medium heat and tip in the onions. Cook slowly, stirring regularly, until completely broken down into a sticky brown tangle (about 30 minutes).
3. Meanwhile, peel the swede and cut into slices the thickness of a pound coin, transferring them to a pan as you work. Cover with plenty of boiling water from the kettle and put over a high heat, then leave to boil while you peel and slice the potatoes to the same thickness. Add the potatoes to the pan with the swede and cook both for 5 minutes more. Drain and leave to cool. In the same pan, wilt the cavolo nero in a splash of water over a high heat, then drain that too.
4. Once the onions have caramelised, stir in the thyme, pickled onions, spring onions, cheddar and mozzarella to form a thick paste, then remove from the heat and stir in the cream to loosen into a sauce. Leave to cool completely.
5. Now you’re ready to make the pie. Roll out two thirds of the pastry on a lightly floured work surface to about 6mm thick and use it to line the cake tin, leaving around 2cm overhang. Put the tin in the fridge until all your fillings have cooled to room temperature.
6. Begin layering the pie. Start with half the potato slices, spread with a quarter of the sauce, then add the cavolo nero, half the swede (adding a good grind of black pepper) and a similar amount of sauce. Tear or chop the taleggio into small pieces and scatter them over, then continue with the rest of the potato and half the remaining sauce. Sprinkle with the chorizo, then finish with the rest of the swede (and more black pepper) and the remaining sauce. Don’t worry if the filling is a little higher than the tin – it will compress and shrink in the oven.
7. Roll out the remaining pastry to form a lid, put it on top of the pie, then crimp the lid and the sides together to seal. Trim off any excess, poke a hole in the centre of the lid with a knife, then brush liberally with most of the remaining egg. Put the pie in the fridge and heat the oven to 180°C fan/gas 6.
8. When the oven is up to temperature, give the pie a final brush with the remaining egg. Bake for 1 hour 15 minutes until deep golden. Leave to cool in the tin for 10 minutes before removing, then wait another 10 minutes before slicing.