Heat the Sichuan peppercorns in a dry frying pan over medium-high heat until just starting to smoke. Then use a mortar and pestle to grind to a fine powder. Set aside for later.
Cut the drained tofu into bite-sized cubes. Heat a saucepan of water over high heat. When the water is at a gentle simmer (don’t rapidly boil the water or the tofu might break up), add a generous couple of pinches of salt. Then carefully add the tofu pieces. Simmer gently for 2-3 minutes then turn the heat off and allow the tofu to steep in the hot, salty water.
Finely dice mushrooms so that they take on the size of ground beef/pork. Marinate mushrooms in 2 tsp of soy sauce and 2 tsp sake, and add a pinch of ground Sichuan peppercorn. Set aside for 10 minutes.
In a wok or large frying pan over high heat, add the vegetable oil. Then add the mushrooms and cook for 2-3 minutes. Then add the douban jiang and cook, stirring for about 2 minutes. Then stir through the garlic, ginger and chili powder. Stir-fry for half a minute. Then add the broth ingredients: chicken stock, soy sauce, dark soy sauce, sugar and vinegar. Bring to a simmer then turn the heat down to medium and cook for 3-4 minutes or until the liquid has reduced by about a quarter and is starting to thicken. Stir through the cornstarch mixture. Now add the rest of the Sichuan peppercorn powder. Taste and season with extra salt or soy sauce if needed.
Now use a slotted spoon to drain the tofu and add it to the pork mixture. Drizzle over the sesame oil and gently toss. Transfer to a serving bowl and sprinkle with green onions. Serve with steamed rice.
