Soak the cedar planks in warm water for an hour or more. In a bowl, mix together the vegetable oil, rice vinegar, sesame oil, soy sauce, and minced garlic. Add in the salmon and let it marinate for about 30 minutes. Start your grill on smoke with the lid open until a fire is established in the burn pot (3-7 minutes). Preheat to 400F. Place the planks on the grate. Once the boards start to smoke and crackle a little, it’s ready for the fish. Remove the fish from the marinade, season it with the onion powder, parsley and black pepper, then discard the marinade. Place the salmon on the planks and grill for about 20 minutes until done. Remove from the grill, let it rest for 5 mins, then serve.