Slice the eggplants into 1cm rounds and soak them in water to remove bitterness. Slice the green onion diagonally and mince the ginger.

Pat the eggplants dry with paper towels. Place them in a plastic bag with cornstarch and shake to coat evenly.

Heat salad oil in a frying pan over medium heat. Add the eggplants and green onion, cooking until the eggplants are golden brown. Remove from the pan.

In the same pan, lightly sauté the minced ginger over medium heat until fragrant. Add mirin and soy sauce, then return the eggplants and green onion to the pan. Cook until the sauce thickens.