2) Preheat the oven to 230C/Gas8. Set a large cast-iron griddle pan over a low heat and pre-heat for 1 min.
3) Meanwhile, brush the salmon lightly with the oil and season with salt and pepper.
4) Raise the heat under the griddle pan to medium-high. Place the salmon, skin-side up on the griddle, at an angle across the ridges of the pan. Cook until the fish has distinctive griddle marks, about 3 mins. To make criss-cross grill marks, use a spatula to re-position the fillets about 45 degrees (keep the skin-side up). Cook for 2 mins more.
5) Turn the salmon over, and transfer the griddle pan to the oven. Continue cooking the fish in the oven for 2 to 3 mins for pink inside, 5 mins for medium, and 7 mins for well done.
6) Remove the fish from the pan, and allow to rest for 2 mins, to finish cooking. (If the skin comes loose during cooking, you may remove and discard it before serving, if desired.) Serve on a bed of cooked rice garnished with lime slices.