Thaw fillets as shown below.
In a small bowl, mix together soy sauce, mirin, honey and sesame oil. Divide in two equal parts. Mix rice vinegar with one of them and reserve it as a dipping sauce.
Spread the sesame seeds on a plate. Drizzle fillets with the remaining portion of the mixture of soy sauce and press the fillets into sesame to cover.
Heat the sunflower oil in a cast-iron skillet until it is very hot. Place the fillets in the pan and fried 30 seconds on each side.
Serve and accompany it with reserved dipping sauce and wasabi paste.