To peel and remove the pith from the grapefruit, firstly roll the grapefruit on a flat surface to loosen the fruit. Cut both ends off the grapefruit so that it can stand upright. Using a sharp knife, carefully cut away at the peel and the pith, following the curve of the grapefruit as carefully as possible. Separate into segments and cut into 1 centimeter cubes.
Place the fillet cubes into a small bowl. In a separate bowl, add the citrus juices, the grapefruit, pepper, onion, tomato, coriander, scotch bonnet and olive oil, mix gently and season to taste with thesalt and pepper. Pour this mixture over the sea-bass and cover with cling film, with the cling-film actually touching the surface of the salad itself, and pop into the fridge to chill for 2 hours.
To serve, arrange the sea- bass on a serving plate. Strain the marinating liquid to separate the juices from the fruit and vegetable. Scatter the vegetable over the sea-bass and drizzle a little of the juice over the sea-bass and sprinkle over a pinch of salt (this dish can really take the salt). Serve immediately.