600 g plain flour, plus extra for rolling
1 tsp fine sea salt
½ tsp baking powder
small bunch fresh thyme, leaves picked and very finely chopped
200 g butter or vegetable shortening
up to 250 mL ice-cold water
Sweet Potatoes and Vegetables
3 sweet potatoes, scrubbed clean
a little butter or olive oil
a few good gratings fresh nutmeg
5 medium beetroots, peeled and cut into rough cubes
splash red wine vinegar
2 sprigs fresh marjoram or oregano, leaves picked
sea salt and freshly ground black pepper
4 parsnips, peeled and cut into little fingers
a couple sprigs fresh sage, leaves picked
zest of 1 unwaxed orange
1 Tbsp honey
25 g butter or olive oil
2 good-sized leeks, washed, trimmed and sliced
3 sprigs fresh thyme, leaves picked
2 heads winter greens, stalks removed, roughly shredded
grated zest and juice of 1/2 unwaxed lemon
1 red chili, finely chopped
200 g Lancashire cheese
1 organic or free-range egg. beaten, or soya milk for brushing
1. First make the pastry. Sift the flour, salt and baking powder into a bowl and add the chopped thyme. Cut the butter or shortening into small bits and rub these into the dry ingredients until you have a breadcrumb-like mix.
2. Add the water and knead to a smooth dough, but don’t overwork it. You could also use a food processor: pulse to breadcrumbs, then add the water and pulse until it just comes together. Wrap the pastry in clingfilm and chill while you get on with everything else.
Sweet Potatoes and Vegetables
1. Now get your veg on the go – all of this can happen at once. Preheat the oven to 220°C/fan 200°C/gas 7.
2. Roast the sweet potatoes for 1 hour until soft. Meanwhile, prepare the beets and parsnips.
3. Pop the beets into a roasting tin, with a splash of olive oil and the vinegar, add the marjoram or oregano, and season. Cover with foil and roast alongside the sweet potatoes for 1 hour, removing the foil for the last 15 minutes.
4. Put the parsnips into a roasting dish with the sage, orange zest, honey and a drizzle of olive oil, mix to coat, then cover with foil. Roast with the other veg for 45 minutes, until golden, removing the foil for the last 5–10 minutes. When all the veg are cooked, remove from the oven and turn the temperature down to 200°C/fan 180°C/gas 6.
5. Meanwhile, cook the leeks. Heat the butter or oil in a large non-stick frying pan. Add the leeks and thyme and cook over a low heat for 20 minutes, until sweet and softened, then set aside.
6. Add a little more olive oil to the pan, add the greens and cook over a low heat for a few minutes, until just wilted. Season, then add the lemon zest and chilli. Set aside.
7. Once the sweet potatoes are cool enough to handle, scoop out the flesh and mash with a knob of butter or 1 tablespoon of olive oil and a good grating of nutmeg. Adjust the seasoning for all the vegetable mixtures, if needed.
8. Take your pastry from the fridge and let it sit for a few minutes. Then roll it out on a lightly floured surface to the thickness of a £1 coin and use it to line a 20cm springform cake tin, leaving the excess hanging over the edges.
9. Now it’s time to start layering the pie. Start with all the leeks, then a grating of Lancashire cheese, then the beets, the greens, and another layer of cheese, then the parsnips and finally the sweet potato mash. Finish by bringing the excess pastry over the top of the mash, twisting the ends and laying them on the mash in a haphazard fashion – the little rough bits of pastry will crisp up and look beautiful. The pastry may not cover the whole of the top, but a little vivid orange sweet potato poking through is okay. Brush with the beaten egg or some soya milk.
10. Bake the pie at the bottom of the oven for 35–40 minutes, until golden brown. Leave to cool for 15–20 minutes, then remove from the cake tin and place in the middle of the table. Serve with lashings of gravy.