Peel and slice the potatoes into matchsticks, then soaked in cold water for 1 hour, then rinse and dry very well.
Heat the olive oil in a large, oven-proof casserole and throw in the cinnamon stick and cardamom pods. Add the chopped vegetables along with a large pinch of salt and cook everything together slowly for 20 minutes, until soft and sweet and lightly caramelised. Add the tomato puree and cook for 1 minute, then add the turmeric and bloom briefly. Pour in the chicken stock.
Meanwhile, brown the lamb well in batches until deeply caramelised, seasoning with salt as you go. Set aside. When ready, add the lamb to the pot along with the thyme, dried limes and bay leaves.
Cover with greaseproof paper and a loosely fitting lid and place in the oven for 4 hours.
Place the knob of butter in a high-sided saute pan and add enough lamb and sauce to create an even layer. Bring to a very light simmer, then lay on the cheese in an even layer, until melted.
Fry the matchstick fries until dark and crisp. Twice-fry the onions, first low and then high, until crisp. Season both with fennel salt.
Spoon the lamb, stringy cheese and sauce all over the bread. Top with the crispy fries and onions, then lots of chives. Enjoy!