For the potatoes
- 3 onions, sliced
- 2tbsp olive oil
- Small bunch of thyme
- 1.5kg large waxy potatoes
- 150ml chicken stock
For the caper gravy
- The bones of the lamb, chopped
- 1 onion, chopped
- 2tbsp plain flour
- 150ml white wine
- 350ml chicken stock
- 2 bay leaves
- 2tbsp large capers, coarsely chopped
- Knob of butter
- 1 saddle of mature lamb or hogget, boned and rolled
- Spring greens
- Redcurrant jelly
- Heat the oven to 200°C/fan oven 180°C/mark 6. Soften the sliced onions in a saucepan with the olive oil and a few sprigs of thyme, without letting them colour. Remove from the heat.
- Peel and slice the potatoes – with a mandolin, if possible – to the thickness of a £1 coin, then rinse in cold water. Place a third of the potatoes in a layer at the bottom of a large, rectangular, ovenproof dish, add half the onions, season well with salt and pepper, and repeat, finishing with a third layer of potatoes nicely arranged on top.
- To make the caper gravy, brown the bones on a tray in the oven for 15 minutes. In the saucepan you used for the sliced onions, colour the chopped onion in the rendered fat from the bones, then add the bones and dust with the flour. Turn this over the heat, then add the wine and 350ml stock, some thyme and the bay leaves. Simmer for at least 1 hour and then strain. Reduce to a gravy consistency then season, add the capers and a knob of butter.
- Pour 150ml chicken stock over the potatoes, then lay a rack or trivet over the dish. Season the saddle all over with salt and pepper, and place it on the rack so the juices drip onto the potatoes. Cook for 25-30 minutes for medium rare. A skewer should be at blood heat (36.5°C) when drawn from the centre of the joint. Remove the saddle and keep warm while it rests
- Continue cooking the potatoes for a further 20 minutes: they should be a lovely golden brown and tender all the way through.
- Serve the carved saddle and the potatoes, with some spring greens, a generous pouring of the gravy and a little redcurrant jelly.