Mash the tofu using a cloth to remove excess water.

Finely chop the onion, carrot, and shiitake mushroom.

In a bowl, mix the mashed tofu, chopped vegetables, egg, cornstarch, breadcrumbs, salt, and pepper to form a dough.

Shape the mixture into steak-sized patties.

Heat a pan with oil and cook the patties on medium-low heat until golden brown on both sides.

For the sauce, sauté minced garlic and sliced onion in a pan with a bit of oil.

Add the sauce ingredients and simmer until slightly thickened.