In a medium bowl whisk together all the relish ingredients except the cucumber. Add the cucumber, stir well, and allow to stand at room temperature for at least 15 minutes.
Prepare the barbecue for direct cooking over high heat (230° to 290°C).
Lightly brush or spray the salmon steaks all over with oil. Season with pepper to taste. Barbecue the salmon over direct high heat, with the lid closed, until opaque throughout, 4 to 5 minutes on each side.
Lightly brush or spray the salmon steaks all over with oil. Season with pepper to taste. Barbecue the salmon over high heat, with the lid closed, until opaque throughout, 4 to 5 minutes on each side.
Serve the salmon with the relish spooned over the top.
