Combine first 7 ingredients for Herb Vinaigrette. Cut fish into serving-size pieces. Brush olive oil on flesh of fish; sprinkle with salt and pepper. Cover a large jelly-roll pan with 1/2-inch deep rock salt. Arrange fish, skin side down on rock salt. Bake in a preheated 400 F oven until fish just flakes with a fork (about 10 minutes per inch measured at its thickest part). Remove from oven, cover loosely with foil, let stand 3-5 minutes.