In a small bowl, blend mayonnaise, teriyaki sauce, and wasabi paste. Place salmon on a large piece of aluminum foil. Spread the mayonnaise mixture over the top of the fillet. Top with green pepper and onion. Season with salt and pepper. Fold the foil around the food and seal into a packet.
Place fish on the preheated grill. Cook for 10 to 15 minutes, or until the fish is easily flaked with a fork.
