Agnello al Forno con le Patate Pugliese

Ingredients

• 2 kg bone-in lamb shoulder or leg, scored at the joints
• 800 g waxy potatoes, Desiree, Charlotte, Sieglinde or Agata; peeled and thickly sliced
• 2 medium white onions, peeled and sliced into rounds
• 300 g cherry tomatoes, whole
• 6 cloves garlic, 2 cloves sliced into slivers for stuffing the lamb; remainder left whole
• 4 sprigs fresh rosemary, broken into short lengths for stuffing the scored joints
• 100 ml dry white wine
• 80 ml extra-virgin olive oil, divided: part for the potato layer, part for the lamb surface
• 1 tsp fine sea salt, divided between potato layer and lamb surface
• ½ tsp black pepper, freshly ground

Method

1. 1
   Heat the oven to 180 °C. Score the lamb deeply at the joints. Into each score, press a sliver of garlic and a short sprig of rosemary. Season the lamb surface with salt and pepper.
2. 2
   Lay the sliced onion across the base of a large roasting pan in an even layer. Arrange the sliced potatoes over the onion, overlapping slightly. Season the potato layer separately with salt, pepper, and a generous drizzle of olive oil — the potatoes require their own seasoning, not only the dripping that will fall from above. Scatter the whole cherry tomatoes and remaining garlic cloves among the potatoes. Pour the white wine over the base. The base should be moist and glistening; if the wine appears insufficient to cover the pan floor, the base will dry out and burn during roasting.
3. 3
   Set the lamb directly on top of the vegetables — it must rest on the potato and tomato bed, not on a rack. Drizzle the remaining olive oil over the lamb so the surface is visibly glistening. This is where the dish lives or dies: the lamb fat and olive oil will render and baste the potatoes continuously from above; if the lamb is elevated away from the vegetables or the pan is covered, neither the caramelisation of the potato surface nor the crisping of the lamb skin can occur.
4. 4
   Roast uncovered at 180 °C for 1 hour 30 minutes. Do not cover the pan at any point. After 1 hour 30 minutes, raise the oven to 200 °C and roast for a further 30 minutes. The lamb skin should be deeply coloured and beginning to pull back from the bone; the potato edges visible above the lamb should show bronze caramelisation.
5. 5
   Remove the pan from the oven. Rest the lamb, uncovered, for 15 minutes in the pan. During this time the juices redistribute and the potato layer continues to caramelise in the residual heat of the pan. The underside of the potato base, when lifted at the edge with a spoon, should be lacquered and dark gold.
6. 6
   Transfer the lamb to a board and carve. Serve the potato and vegetable base directly from the pan. Pour the collected pan juices over the carved lamb and potatoes at the table. No separate sauce is made.