1. Pat salmon dry between paper towels and sprinkle with salt and pepper. In a 12-inch non-stick skillet heat oil over moderately high heat until hot but not smoking and sauté salmon, skin side down, 3 minutes. Reduce heat to moderate and cook salmon 4 minutes more. Turn salmon and sauté over moderately high heat 2 minutes. Reduce heat to moderate and cook until just cooked though, about 3 minutes more.
2. In a food processor blend pesto with 1 tablespoon hot water, adding additional hot water if necessary to reach desired consistency.
3. Serve pesto over salmon.