1. Add the lamb trotters and coriander roots to a vessel and boil it. Then strain it with a conical strainer. Add oil and onion juliennes to another vessel and sauté it till the onions turn golden-brown. Add the ginger-garlic paste, black pepper, chilli powder, salt, green chillies, and the whole coriander and cook it well.
2. Transfer the lamb trotters to this vessel, add the lamb stock, and let it boil till the bone marrow turns soft and the stock turns thick. Serve it hot, in a bowl, sprinkled with golden-brown crispy onion, served with sheermal.