In a big pot, add 1.5 litres of water and boil the prawn heads & shells until flavours are released. Remove prawn heads & shells.
Add rempah and half of the laksa leaves into pot and bring to a boil.
Add coconut milk and laksa leaves into the pot and simmer for 5 minutes. Add concentrated chicken stock, salt and sugar, and adjust according to preference.
Meanwhile, boil the tofu puffs in another pot for just a while. Remove from pot and slice into strips. Add tofu puffs into laksa gravy and simmer for another 5 minutes.