Combine the ginger, sesame seeds, soy sauce, rice vinegar and sugar in a bowl, and then set aside. Heat the oil in a large non-skillet over medium-high heat. Season the trout with pepper. Place the fish in the skillet flesh-side down and cook 3-4 minutes. Carefully flip fish over and cook 3 minutes more. Transfer fish to 2 dinner plates, spoon over reserve soy sauce mixture, sprinkle with green onions, and serve.