Roast mutton shoulder with roast potatoes

Method

1. Trim most of the fat from the mutton shoulder, leaving just a very thin layer, then score the remaining fat. Toast the cumin, coriander, allspice and peppercorns in a dry pan for a few minutes until fragrant, then transfer to a blender. Add the sugar, salt, preserved lemons, paprika, vinegar and half a red onion and whizz into a paste. Rub this paste all over the mutton, really pushing it into any gaps and folds. Set aside for 30 minutes.
2. Meanwhile, heat the oven to 200°C fan/gas 7. Finely slice the remaining 1 1⁄2 onions and peel, finely slice and rinse the potatoes. Put the mutton in a large roasting tin and roast in the oven for 40 minutes, then remove. Carefully lift the mutton out of the dish, set to one side, then drizzle the pan with oil and add the potatoes, sliced fennel, sliced onions, fennel seeds, ground pepper and a generous pinch of salt. Pour in the stock, put the mutton back on top, then cover with foil and return to the oven. Turn the heat down to 140°C fan/gas 3 and cook for 4 hours.
3. Remove the foil and carefully lift the mutton out of the potatoes and set aside to rest. Return the potato dish to the oven (uncovered), turn the heat up to 200°C fan/gas 7 and cook for another 20 minutes until the potatoes on top are golden.
4. Remove the potatoes from the oven, cover loosely with foil and leave to rest for 20 minutes. Serve the potatoes either alongside or underneath the mutton and bring to the table alongside your favourite greens.