How to Make It
In a small bowl, soak the currants in warm water until plumped, about 15 minutes, then drain them. In a small skillet, toast the pine nuts over moderate heat until lightly golden, about 4 minutes.
In a large, deep skillet, heat the 1/4 cup of olive oil until shimmering. Add the onions and a generous pinch each of salt and pepper and cook over moderate heat, stirring occasionally, until the onions are softened and light golden, about 15 minutes. Add the wine, vinegar, sugar and bay leaf and simmer for 10 minutes, stirring occasionally. Discard the bay leaf and keep the onions warm.
Meanwhile, light a grill or preheat a grill pan. Brush the fennel wedges with olive oil and season with salt and pepper. Grill the fennel over moderate heat, turning occasionally, until crisp-tender and lightly charred, about 10 minutes. Transfer to a plate.
Brush the swordfish steaks with olive oil and season with salt and pepper. Grill the fish over moderately high heat until nicely browned outside and just white throughout, about 3 minutes per side. Spoon the onions onto plates and arrange the swordfish steaks on top. Scatter the currants and pine nuts over the fish and serve with the grilled fennel.