For the madras curry powder, place all of the curry powder ingredients into a spice grinder and grind to a fine powder.
For the lamb madras, season the lamb shanks all over with salt and freshly ground black pepper. Heat the vegetable oil in a large non-stick casserole pan and sear the lamb shanks for 1-2 minutes on all sides, or until golden-brown all over. Remove the lamb shanks from the pan and set aside.
Blend the chilli, garlic and ginger in a small food processor to a paste, adding a splash of water if necessary.
Place the pan used to cook the lamb back over a high heat and add the onions (add a splash of oil to the pan if it is too dry). Fry for 2-3 minutes, or until softened and starting to colour.
Add 2½ tablespoons of the curry powder to the pot along with the garlic, chilli and ginger paste, curry leaves, cardamom and bay leaves. Stir well.
Return the lamb shanks to the pan and cover with the chopped tomatoes, beef stock and tamarind juice. Season, to taste, with salt and freshly ground black pepper. Cover the pan with a lid simmer over a low heat for 2 hours, or until the lamb is very tender.
Meanwhile for the chapatis, sift the flour and salt into a large bowl and gradually mix in enough of the water to form a soft dough (you may not need all of the water). Cover and set aside to rest for 10 minutes.
Turn the dough out onto a floured work surface, lightly knead and then divide equally into 12 balls. Roll out each ball as thin as possible.
Heat a frying pan over a high heat and add the oil. Cook the chapatis one at a time, frying for 1-2 minutes on both sides or until golden-brown and puffed up.
For the fried shallots, dust the sliced shallots in the flour. Heat the vegetable oil in a frying pan over a high heat and fry the shallots for 2-3 minutes, or until golden-brown and crisp. Remove from the oil and drain on kitchen paper.
To serve, remove the lamb shanks from the pan and place one on each serving plate. Place the pan back over a high heat and simmer until the liquid has reduced to a thick sauce, enough to coat the back of a spoon. Pour the sauce over the lamb shanks and garnish with the crisp shallots. Serve the chapatis on the side.