Trim and halve the spring onions, finely shred lengthways and place in a bowl of ice-cold water to crisp up. Pick in the coriander leaves, reserving the stalks.
Place a large non-stick frying pan on a medium-high heat. With a sharp knife, score the sea bass skin at 2cm intervals, then rub all over with the curry paste, inside and out, getting into all the cracks and crannies. Pack the coriander stalks into the cavities, season with sea salt and black pepper, then place in the hot pan with 1 tablespoon of olive oil. Cook for 3 to 4 minutes per side, or until dark golden and cooked through (depending on the thickness of your fish).
Drain and shake off the spring onions and coriander and pile on to your plates. Sit the sea bass on top, spooning over any spicy oil from the pan. Finely grate over the lime zest, and serve with lime halves, for squeezing over.