Mince the onion and slice the shiso leaves. Microwave the onion in a heatproof container for 1 minute at 600W, then let it cool.

Wrap the tofu in kitchen paper and microwave for 1 minute 30 seconds at 600W to remove excess moisture. Let it cool.

Finely chop the horse mackerel fillet and mash it until sticky.

In a bowl, combine mashed horse mackerel, crumbled tofu, onion, shiso leaves, ginger, and the seasoning ingredients. Mix well and shape into two oval patties.

Heat salad oil in a frying pan over medium heat. Cook the patties until browned on one side, then flip, cover, and cook on low heat for 3-4 minutes until cooked through.

Remove the lid and push the patties to the side of the pan. Wipe off excess oil and residue with kitchen paper.

Add the teriyaki sauce ingredients to the pan and simmer over medium heat. Coat the patties evenly with the sauce.