There are a few substitutions within the recipe, below, but otherwise I suggest you try this dish as-written the first time you make it. Decrease the amount of chile oil for a milder flavor, or add more if you like the heat! Then, adjust the wine, soy sauce, sesame oil and sugar to your liking
Combine the shiitake mushrooms and cup of warm water in a mixing bowl. Soak for 15 to 20 minutes, then lift out the mushrooms and transfer to a cutting board, squeezing as much moisture out of them as you can back into the bowl. Reserve the soaking water, straining it through a fine sieve if it has grit or dirt. Discard the stems, then finely chop the shiitake mushroom caps.
Add the chili bean paste, rice wine, soy sauce, sesame oil, sugar and Sichuan pepper (to taste) to the bowl of mushroom soaking water, stirring to incorporate. This will be your sauce.
Heat a wok or large skillet over medium-high heat. It is hot enough when a bead of water sizzles and evaporates on contact.
Add the peanut or vegetable oil and swirl to coat. Add the mushrooms; stir-fry for 2 minutes, until the mushrooms are crispy. Reduce the heat to medium; add the black bean sauce, white parts of the scallions, garlic and ginger; stir-fry for about 1 minute, until fragrant.
Pour in the mushroom-mixture sauce; once the liquid starts to boil, reduce to a gentle bubbling over medium-low heat. The liquid in the pan should now be a nice red color. Gently add the tofu cubes, being careful to not move them around too much so they don't break up. Cook for 2 to 3 minutes so the tofu absorbs the sauce. You can spoon some of the sauce over the tofu cubes to help better coat them.
Carefully push the tofu to the sides and create a small well at the center of the pan. Stir in the cornstarch mixture there. Cook for another minute, until the sauce has thickened enough to coat the back of a spoon.
Transfer to a deep plate or wide bowl, sprinkle the scallion greens on top with additional Sichuan pepper as needed, and serve hot.
Adapted from a recipe by Diana Kuan at cinnamonsociety.com.