Preheat the oven to 140°C/fan 120°C/ gas mark 1.
Toast the seaweed sheets and sesame seeds in a dry pan until the seaweed is crisp and the seeds golden, then set aside to cool. Once cooled to room temperature, blitz in a food processor with a generous pinch of salt to create a coarse dust. Tear the kale leaves into bite size pieces, discarding the stems, then massage with rapeseed oil and dust all over with the seaweed mix. Bake in the oven (checking often) for around 30 minutes, or until crisp, then set aside.
Heat a little rapeseed oil in a frying pan and cook the mackerel fillets skin side down until crisp and caramelised, then turn over and take the pan off the hob. Allow the mackerel to continue cooking in the residual heat to ensure it is tender and flaky.
Combine the mango, red onion, red chilli, lime juice and zest with most of the coriander in a bowl to create a salsa. Season to taste
Cook the coconut rice as per pack instructions, set aside to cool, then mix in some of the miso and citrus dressing.
Split the dressed rice between two bowls, top with some mango salsa, a mackerel fillet and a handful of crispy kale. Finish with spring onions and the extra coriander.
Optional topping: half an avocado, fanned, and some crispy shallots or onions.