Remove skin from the mackerel and flake into large pieces and set aside in a large mixing bowl.
Slice the skin from the oranges and either slice into rounds or segments and add to the bowl.
Finely slice the shallot into rounds and add those to the bowl, along with the leaves picked from the herbs.
Finely slice the chillies and whisk together with fish sauce, lime juice, sugar and 1 tbsp cold water in a separate bowl to make the dressing.
Just prior to serving, coat the mackerel, citrus and herb salad in the dressing and toss well before dividing between serving dishes.
Recipe: with kind permission of Tom Rhodes (Masterchef 2021 Winner)