Soften trotters and shanks in pressure-cooker
OR cook covered on low heat in just enough hot water to cover, until tender.
Sauté onions with sugar until golden-brown
Add half the chopped coriander and fry
Add spice paste and salt and mix well
Fry on low heat, sprinkling hot water if necessary to avoid the mixture sticking to base of pan
Add tamarind pulp and simmer covered for about 10 minutes, on low heat
Then add trotters and shanks and their gravy and mix well with the other ingredients
Simmer covered on low heat for at least an hour, stirring occasionally, until meat is falling off the bone
Taste for salt, chilli and vinegar
Add green chillies and remaining coriander, stir well, and simmer covered for another 10 minutes.
Keep overnight in fridge (it tastes better the next day!)
Serve with slices of crusty bread or steamed white rice, and vegetables