This is a traditional Malay recipe from my sister-in-law, Molly. You can substitute the prawns for fish or chicken. Note that if using chicken, it will take a longer time to cook.
300g (11oz) large tiger prawns
250ml (8fl oz / 1cup) boiling water
375ml (12fl oz / 1½cups) thick coconut milk
1stalklemongrass, white part only, bruised
150g (5⅓oz) pineapple, cut into cubes (optional)
Salt, to taste
6shallots, peeled and roughly chopped
2green chillies, roughly chopped
6bird’s eye chillies, or to taste
125ml (4fl oz / ½cup) water
Peel and devein the prawns. Reserve the heads and shells. Rinse the prawns and set aside.
Place the prawn heads and shells in a pot. Add the boiling water and simmer for 15 minutes. This will be the stock for the dish. Strain the stock and discard the heads and shells (see Note).
Place all the ingredients for the spice paste in a blender and process into a coarse paste.
Transfer the spice paste to a medium saucepan. Add the stock, coconut milk, lemongrass, turmeric powder and asam gelugor. Bring to a boil while stirring continuously to prevent the coconut milk from curdling.
Add the pineapple and turmeric leaf. Season with salt.
Add the prawns and stir gently. Turn down the heat and let it simmer for 2 minutes until the prawns are done. Remove from heat.