Step 1

Preheat the oven to 180°C.

Step 2

Combine coconut milk, lemongrass, garlic, ginger, sugar, chilli, fish sauce, lime juice, kaffir lime leaves and curry paste in a saucepan over medium heat. Bring to a simmer, stirring, then set aside for 10 minutes to infuse.

Step 3

Meanwhile, place potato in a saucepan of cold salted water over high heat. Bring to the boil, then simmer for 12 minutes or until tender. Drain, then mash, add the butter and milk, season and beat with a wooden spoon until smooth and creamy.

Step 4

Place the fish, prawns and peas in a 1.2L baking dish. Remove lemongrass and whole lime leaves from the sauce and discard. Add the coriander, then pour over the seafood.

Step 5

Top with the mashed potato, raking the surface with a fork, and dot with extra butter.

Step 6

Bake for 25-30 minutes until the top is golden and seafood is cooked, then serve.