Preheat oven to 450°F. Center onion and carrot on foil sheet. Top with Alaska Salmon fillet portions. In small bowl, combine ginger, rice vinegar and sesame oil. Pour over salmon. Season with salt & pepper. Wrap and seal foil to form a packet. Cook covered, 20 to 25 minutes on medium-hot grill or until fish flakes easily with a fork. Serve salmon topped with onion and carrots on a bed of spinach. Sprinkle with additional seasoned rice vinegar, if desired.