Step 1 Use a mortar and pestle to lightly bruise the chillies. Set aside for later. Step 2 Place coconut milk, 1/2 cup water, lemongrass, galangal and makrut lime leaves in a saucepan over high heat. Bring to the boil. Then add the chicken and mushrooms. Reduce the heat to medium and simmer for 4-5 minutes or until the chicken is cooked through. Remove from heat. Step 3 Stir through the bruised chillies, fish sauce, lime juice and sugar. Taste and season with extra fish sauce or lime juice to taste. The flavour should be creamy and tangy. Step 4 Just before serving, stir through the coriander.