Preheat broiler. Line a broiler pan or baking sheet with foil, then coat it with cooking spray.
Place salmon pieces, skin-side down, on the prepared pan. Season with salt and pepper. Combine sour cream, mustard and lemon juice in a small bowl. Spread evenly over the salmon.roil the salmon 5 inches from the heat source until it is opaque in the center, 10 to 12 minutes. Serve with lemon wedges.