Step 1

Preheat the oven to 160°C. Season the lamb with salt. Heat the oil in a flameproof casserole over medium-high heat. Cook the lamb, in batches, turning, for 6 minutes or until browned all over, then remove from the pan. Reduce heat to medium, add the onion and cook, stirring, for 3-4 minutes until softened. Add the garlic and ginger, then cook, stirring, for a further 1 minute. Add spices, bay leaves and chillies, and cook for 30 seconds or until fragrant. Add the yoghurt, stock and sour cream, then stir to combine.

Step 2

Return the lamb to the casserole, season with pepper and bring to a simmer over medium heat. Cover surface with baking paper cut to fit, then cover with a lid, and place in the oven for 2 hours or until the meat is tender.

Step 3

Meanwhile, place the potatoes in a saucepan of cold salted water. Bring to the boil over medium heat and simmer for 12-15 minutes until tender, then drain.

Step 4

Add the potatoes to the curry and stir to combine. Scatter with coriander and serve with naan.