Recipe from The Hairy Bikers' Great Curries by Si King and Dave Myers published by Weidenfeld & Nicolson (£20, hardback)
- 5 tbsp sunflower oil
- 4 large onions, sliced
- 10 cardamom pods
- 1 tbsp cumin seeds
- 2 tsp mustard seeds
- ½ cinnamon stick
- 2 long red chillies, sliced
- 6 large garlic cloves, roughly sliced
- 1 tbsp ground coriander
- 2 tsp ground turmeric
- 500g mature spinach leaves (not baby spinach), washed and drained
- 900g boneless lamb leg, cut into chunks of about 4cm
- 1 bay leaf
- 2 tbsp tomato puree
- 800ml cold water
- 1 tsp flaked sea salt, plus extra for seasoning the lamb
- freshly ground black pepper
Heat 3 tablespoons of the sunflower oil in a large non-stick frying pan. Cook the onions gently for 20 minutes until softened and golden brown, stirring regularly.
Place the cardamom pods in a pestle and mortar and pound lightly to split the pods. Tip them on to a board and open each pod, scraping the seeds back into the mortar. Add the cumin, mustard seeds and the cinnamon stick. Pound to form a fairly fine, dry powder.
When the onions are ready, transfer about half of them to a plate and set aside. Return the pan to the heat and stir in chillies and garlic and cook for 3 minutes, stirring. Add the pounded spices, ground coriander and turmeric. Cook for 2 minutes more, stirring constantly.
Break off any tough stalks from 300g of the spinach, drop the leaves into the pan and cook for 2–3 minutes, turning it with the onions until well wilted. Remove the pan from the heat, scrape everything into a heatproof bowl and leave to cool. Get rid of any tough stalks from the remaining spinach and tear the leaves in half. Cover and set aside.
Return the pan to the heat and add another tablespoon of oil. Season the lamb all over with salt and freshly ground black pepper. Fry the lamb over a medium-high heat in 2 or 3 batches until browned on all sides, adding more oil if necessary. As soon as a batch is browned, transfer it to a medium flameproof casserole dish while you fry the rest. Preheat the oven to 170°C/Fan 150°C/Gas 3 ½
Transfer the spiced onions and spinach to a food processor and blitz to a thick green paste. Stir this into the casserole dish with the lamb and add the bay leaf, tomato puree and water. Season with the teaspoon of flaked sea salt, stir well and bring to a simmer.
Remove the casserole dish from the heat and cover the surface of the curry with some crumpled baking parchment. Pop a lid on top and cook the curry in the oven for 2.–3 hours or until the meat is very tender and the sauce is thick. Stir halfway through cooking if possible. Take the curry out of the oven and stir in the reserved onions and the rest of the spinach. Cover with the lid alone and return to the oven for a further 15–20 minutes or until the onions are hot and the spinach has wilted. Serve with freshly cooked rice or warm naan.