Instruction

• step 1 Pour 1
• 3 litres water into a large saucepan over a high heat
• Add the onion, tomato, chilli, galangal, lemongrass, prawn heads and chicken stock cube
• Stir and bring to a boil, then reduce the heat to medium and simmer for 20 mins until the liquid has reduced
• step 2 Carefully strain the hot broth into a large heatproof bowl or jug, then discard the prawn heads
• Return the strained veg and herb mixture to the saucepan and pour over the broth
• Stir through the mushrooms and lime leaves, then cook for 3 mins until the mushrooms are tender
• step 3 Add 1 tbsp sugar, the fish sauce, lime juice, coconut milk and prawns
• Bring to the boil and cook until the prawns are cooked through, about 1-2 mins
• Remove from the heat
• Remove the lemongrass, then stir in the Thai chilli jam, if using
• Scatter over the coriander to finish, if you like, and serve