Preheat the oven to 200°C. Blanch the broccoli till tender then drain. Put the broccoli in the centre of the baking paper (that has been placed on top of the foil). Sit the fish on top and scatter over the ginger, lemongrass, chilli and spring onion. Mix the coconut milk and fish sauce and spoon over each piece of fish. Scrunch up into a parcel and cook for 20 minutes.