Agnello con salsa di rafano (Piedmontese roast lamb with horseradish sauce)

For ➏
1 kg rack from a young lamb
½ leek, finely sliced
1 rib of celery, sliced
1 carrot, sliced
4 leaves fresh sage
1 sprig of rosemary
75 g unsalted butter
3 tbs olive oil
450 g renette apples
50 g freshly grated horseradish
2 tbs sugar
3 dl good broth
15 cl red wine vinegar
salt & pepper

Begin by peeling and coring the apples.
Preheat your oven to 180° C. Dot a baking dish with the butter and drizzle the olive oil over it. Set the lamb into the dish and sprinkle the chopped vegetables and herbs around it. Season the lamb with salt and pepper, cover the dish, and roast the lamb for about 40 m. Baste it with pan juices every now and again.
In the meantime prepare the sauce. Blend the apples with the horseradish, sugar and vinegar, adding sufficient broth to make a liquid sauce.
When the meat is fork-tender, slice it.

Arrange the slices in a deep heatproof serving dish. Spoon the applesauce over it, heat the dish through in the oven, and serve it.