Place the dried shiitake mushrooms in a bowl, cover with the 1 cup warm water, and soak for 15-20 minutes, until the mushrooms are soft. Drain the mushrooms, squeeze out excess water, and reserve the liquid. Discard any tough mushroom stems and finely chop the caps.

In a small bowl, stir together the mushroom soaking liquid, mirin, soy sauce, sesame oil, and honey.

Heat a wok or large skillet over medium-high heat. Add the oil to coat the bottom of the wok. Add the mushrooms and black bean sauce to the wok and stir fry until the mushrooms are crisp.

Reduce the heat to medium, add garlic and ginger and stir fry for 1 minute. Pour the sauce into the wok, and reduce to simmer.

Gently add the cubed tofu to the wok and simmer for 3 minutes to allow the tofu to absorb some of the sauce.

Create a well in the center, stir together the cornstarch with 2 tablespoons of water. Stir the cornstarch mixture into the sauce and cook for 1 minute, until thick. Top with the scallions and serve.