Rinse the rice well in a sieve and then put into a pan with the water and a pinch of salt. Bring to the boil, then reduce the heat and cover with a lid. Simmer for 25 minutes without lifting off the lid, then turn off the heat and leave to sit for another 10 minutes for perfectly cooked rice (or simply cook according to packet instructions). This rice can sit happily for up to 30 minutes with the lid on.
Heat a heavy-based griddle pan. Score the skin of the sea bass fillets three times on each side and smear all over with the oil, then season with a pinch of salt and plenty of pepper. Add to the griddle pan, skin side down. Cook for 2 minutes, then turn over and cook for a further 2 minutes, until the fish fillets are cooked through and tender. Test with the tip of a sharp knife – the flesh should come away easily.
Meanwhile, make the salsa, put the cherry tomatoes, yellow or orange peppers, avocado, chilli, spring onions and coriander in a bowl. Season with a pinch of salt and plenty of pepper. Cut the lime into wedges and reserve four to garnish. Squeeze the rest into the salsa and gently fold together to combine.
Spoon the wholegrain rice onto warmed plates and place a piece of the chargrilled sea bass on each one with a mound of the salsa to the side. Garnish with the lime wedges to serve.