Prepare a hot fire in a charcoal grill or heat a gas grill or broiler. Away from the heat source, lightly coat the grill rack or broiler pan with cooking spray. Position the cooking rack 4 to 6 inches from the heat source.
In a small bowl, combine the basil, parsley, minced garlic and lemon juice. Spray the fish with cooking spray. Sprinkle with black pepper. Top each fillet with equal amounts of the herb-garlic mixture. Place the fish herb-side down on the grill. Grill over high heat. When the edges turn white, after about 3 to 4 minutes, turn the fish over and place on aluminum foil. Move the fish to a cooler part of the grill or reduce the heat. Grill until the fish is opaque throughout when tested with the tip of a knife and an instant-read thermometer inserted into the thickest part of the fish reads 145 F (about 4 minutes longer).
Remove the salmon and place on warmed plates. Garnish with green olives and lemon slices.