Peel, segment, and dice the grapefruits and orange, letting the segments and any juices fall into a bowl. Add cilantro and mint and stir gently. Set aside.

Season the sea bass fillets with salt and pepper.

In a heavy frying pan over medium-high heat, heat the olive oil. Add the seasoned sea bass and cook until browned underneath, three to four minutes. Turn the sea bass over and cook until opaque around the edges, about three minutes more.

Transfer the sea bass to individual plates. Spoon the grapefruit-mint mixture on top and drizzle with a little olive oil. Serve immediately.