Slow-roast lamb with potato & spinach gratin

Lamb shoulder is so much cheaper than leg and responds really well to long, slow cooking. The gratin cooks at the same temperature so can cook alongside the lamb. ■ Serves 6 ■ Prep 30 mins ■ Cook 4 hrs

2 sprigs rosemary, needles chopped

1/2 lemon, juiced olive oil

1.2kg boned lamb shoulder, rolled and tied

1 glass white wine

400g shallots, peeled

FOR THE GRATIN

300ml double cream

300ml whole milk l whole nutmeg

1 garlic clove, halved

2 tsp Dijon mustard

400g spinach butter, for the dish

1.5kg potatoes, peeled and thinly sliced 50g grana padano, grated

1 Heat the oven to 160C/140C fan/gas 3. Mix the rosemary, juice, a little oil and 1 tsp sea salt and rub over the lamb in a roasting tin. Cook for 2 hrs (basting a few times). Add the wine and shallots; cook for another 2 hrs. 2 For the gratin, heat the cream and milk, stirring in some nutmeg, the garlic clove and the mustard. Season well then turn off the heat and sit 10 mins. Take out the garlic.

3 Put the spinach in a colander and pour over boiling water to wilt. Cool then tip into a clean tea towel and squeeze out as much water as possible. Season and add more nutmeg. Butter a large ovenproof dish. Layer up the potatoes and spinach, adding cream as you go. Finish with a layer of potatoes and push down so the cream just comes to the surface. Scatter over the cheese. Cover with foil and bake alongside the lamb for the last 11/2 hrs, removing the foil after 45 mins.

PER SERVING 948 kcals, fat 61g, saturates 33g, carbs 47g, fibre 8g, protein 49g, salt 1.9g