Cut the grilled eel into 1cm cubes. Thinly slice the cucumber, sprinkle with 1/3 tsp salt, rub, and squeeze out excess water. Finely chop the pickled ginger.

In a bowl, mix the sushi seasoning ingredients (vinegar, sugar, salt, sesame seeds).

Add the warm rice to the bowl, pour in the sushi seasoning, and mix gently. Add the eel, cucumber, pickled ginger, and sesame seeds, and mix well.

Divide the seasoned rice into 4 portions, wrap each in plastic wrap, and shape into balls.

Mix the cornstarch and water to create a slurry. Blanch the mitsuba briefly in hot water. Combine the egg mixture ingredients (eggs, sake, salt) with the slurry.

Heat a frying pan with a little salad oil. Pour 1/4 of the egg mixture into the pan and cook on low heat until set. Flip briefly to cook the other side. Repeat to make 4 thin omelets.