2) Heat the oil, about 4 tablespoons, in a large skillet over medium to medium-high heat. If your pan is not large enough to fry four fillets, in a single layer, heat the oven to 140C/Gas 1 and put a cooling rack on a baking sheet. As you fry the fish, transfer them to the rack in the oven to keep warm. Fry the fish until deeply golden and crispy and transfer to a serving platter.
Season with a little extra salt, top with lots of lime juice and serve.