Place the fillets in a single layer in a 13 x 9-inch baking dish, and sprinkle with 1/4 teaspoon salt. Combine 1/2 teaspoon salt, cilantro, and the next 7 ingredients (cilantro through garlic clove) in a blender or food processor, and process until smooth. Pour cilantro mixture over the fillets, and turn to coat. Marinate in the refrigerator 30 minutes, turning once.
Remove fish from dish; discard marinade. Place fish on grill rack coated with cooking spray; grill 5 minutes on each side or until fish flakes easily when tested with a fork. Garnish fish with chopped chives and lime wedges, if desired.
Note: Store cooked fillets in refrigerator for up to 1 day.