1. Add all ingredients in a large saucepan and bring to boil.
2. Remove from the flame when the water is reduced to almost 5 cups and the lamb is cooked well.
3. Strain the soup in a large sieve.Keep aside.
4. In a fry pan add the clarified butter and sautee the onion kept for seasoning till brown in color.
5. Add the cornflour till its done.
6. Add salt and pepper and add this mixture to the soup and boil on a low flame.
7. Splutter the mustards in clarified butter kept for seasoning and fry the shallots till brown.
8. Remove the soup from fire and add the garnish on top.
9. Serve hot.