Vegetarian Mapo Tofu with Shiitake

Steps

1. Start the rice first; everything else happens while it cooks. Rinse the Japanese short-grain rice 3 times in cold water, rubbing it between your fingers, until the water runs almost clear, then drain. Put it in a saucepan with 360 ml (1 1/2 cups) of water, bring to a boil, cover, turn the heat to very low, and cook for 12 minutes. Turn off the heat and let it rest 10 minutes without lifting the lid.
2. Remove the shiitake stems and chop the caps with a knife into small, lentil-size bits. Finely mince the garlic and the peeled ginger. Slice the scallions, keeping the whites and greens separate. Cut the silken tofu into 2 cm (3/4 inch) cubes, holding it in your palm or on a wet cutting board so it slides off without breaking.
3. Toast the Sichuan peppercorns in the dry wok over medium heat for 2 minutes, stirring, until they darken slightly and smell strong. Transfer to a mortar and crush into a coarse powder. In a small bowl, stir the cornstarch into 60 ml (1/4 cup) of cold water.
4. Bring 1.5 liters (about 6 cups) of water to a simmer in a saucepan with the salt. Slide in the tofu cubes and leave them 3 minutes in barely simmering water, never a rolling boil, which would break them. The salt firms the surface of the tofu and removes its raw soy taste, so it holds together as it simmers. Lift them out gently with a slotted spoon and set aside in a bowl.
5. Wipe out the wok and heat 4 tablespoons of oil over high heat until it shimmers. Spread the shiitake in a single layer and leave them alone for 3 minutes, then stir-fry for 3 minutes more: they should release their water, cook it off, and end up brown, dry, and sizzling, with crisp edges.
6. Push the shiitake to the side of the wok, lower the heat to medium, and add the last 1 tablespoon of oil to the center with the doubanjiang. Fry it for 1 minute, mashing it with the spatula, until the oil turns brick red and fragrant. Add the rinsed and roughly mashed fermented black beans, the garlic, ginger, scallion whites, and ground chili, and stir for 30 seconds, just until fragrant, without letting anything burn.
7. Stir everything together with the shiitake, pour in the vegetable broth, light soy sauce, and sugar, and bring to a simmer. Slide the tofu cubes into the sauce and nudge them gently with the back of a ladle rather than a spoon, shaking the wok. Simmer for 4 minutes at a gentle bubble so the tofu soaks up the sauce.
8. Thicken the sauce in 3 rounds: stir the slurry (the starch settles to the bottom), drizzle one third around the edge of the wok, shake gently, and let it bubble for 30 seconds. Repeat with the second third, then judge: stop as soon as the sauce coats the tofu and turns glossy, and add the last third only if it is still too thin. Taste and adjust with a few drops of soy sauce.
9. Pour the mapo tofu into a shallow serving dish and sprinkle with the ground Sichuan pepper and scallion greens. Fluff the rice with a fork and serve right away, piping hot, with the sauce spooned over the rice.