Lamb shank hotpot pie with pickled red cabbage

Method

1. To make the pickled cabbage: put the red cabbage in a large heatproof non-reactive bowl. Put the onion, vinegar and sugar in a small stainless steel saucepan over a high heat and boil for about 10 minutes until the onion starts to soften. Pour the mixture over the cabbage, stir well, then leave to cool completely. Cover and chill to pickle overnight or until needed (see Make Ahead).
2. For the pie, season the flour with salt and pepper, then toss with the lamb shanks. Heat the oil in the pan/casserole, then brown the shanks all over. Add any remaining seasoned flour to the pan/casserole along with the onions, carrots, potatoes, garlic and rosemary and stir well. Pour in the stock, topping up with a little water if needed to cover the meat. Bring to the boil, then cover and simmer very gently for 2 hours or until the meat is falling off the bone. Remove the meat from the pan. Reserve 3 of the bones, then shred the meat. Reduce the cooking liquid to about 2 litres by bubbling over a medium heat, if you need to.
3. Heat the oven to 200°C/180°C fan/gas 6. Transfer the lamb and liquid to the pie dish, putting the reserved lamb bones on top in a line down the centre, then leave to cool.
4. Roll out the pastry on a lightly floured surface until 4mm thick and large enough to cover the pie. Brush the rim of the dish with a little beaten egg, then cut 3 slits in the rolled-out pastry to match the bones. Lay the pastry lid over the top, sliding the bones through the slits. Press down the edges of the pastry to seal, then trim off any excess pastry and crimp the edges with your fingers or a fork. Brush with beaten egg to glaze (see Make Ahead).
5. Bake the pie for 30-40 minutes until the pastry is puffed and golden and the filling is bubbling. Serve with the picked red cabbage alongside.