Cut off the eggplant stems and slice into bite-sized pieces. Thinly slice the white part of the green onion.

Layer 2 slices of pork belly, season with salt and pepper, and fold tightly into 2cm wide rolls. Repeat to make 6 rolls and coat lightly with cornstarch.

Heat salad oil in a frying pan over medium heat. Place the pork rolls seam-side down and cook until browned, turning occasionally until fully cooked.

Add the eggplant to the pan and stir-fry until softened. Turn off the heat.

Add the seasoning mixture (sake, mirin, sugar, soy sauce) to the pan, return to medium heat, and simmer while stirring until thickened.