Preheat the oven to 180°C, fan 160°C, gas mark 4. Cut 4 large circles of greaseproof paper.
Mix together the lemongrass, ginger, chilli, carrots and courgette, and divide between the paper circles.
Top each with a coley fillet, then sprinkle over the lime juice and zest. Fold the paper circles into loose parcels.
Put the parcels on a baking sheet and bake in the oven for 15-20 minutes.
Meanwhile, cook the noodles to pack instructions. Drain and mix in the sesame seeds, soy sauce, 100ml of water and half the coriander.
Open the fish parcels, scatter over the remaining coriander and serve with the noodles.