Remove the skin from the swordfish. Butterfly the fish. Lightly flour both sides of the steaks.

Heat the oil to shimmering so the pan is really hot. Sear the fish on both sides. About 3 minutes per side. Remove the fish from the pan, reduce the heat and melt the butter. Swirl in the wine and lemon juice. Add the other ingredients and cook until the spinach has wilted and the butter sauce coats the back of a spoon. Serve the fish on top of the sauce.