First, make the chilli paste. Cut chilli in half lengthways and scrape out seedsusing a spoon. Finely dice chilli and pound to a fine paste with salt, chilli flakes and peppercorns using a mortar and pestle, blender or small food processor.
Stir in vegetable oil and set aside.
Gently remove tofu from packet and invert onto a plate. Carefully cut into 20 cubes by cutting lengthways into four equal slices, then widthways into five slices, draining off any excess liquid.
Meanwhile, heat oil in a hot wok until surface seems to shimmer slightly.
Add pork and stir-fry for 3 minutes. Remove pork with a slotted spoon and set aside.
Add chilli paste to wok with ginger, garlic and black beans, then reduce heat and stir-fry on low heat for 2 minutes, stirring constantly.
Return pork to wok with wine and stir-fry for 1 minute. Add soy sauce and sugar and stir-fry for 30 seconds. Pour in water and bring to the boil. Reduce heat to a gentle simmer and carefully slide tofu into wok, gently separating the cubes as they fall into the pork mixture. Simmer, covered, for 3 minutes.
Spoon into a shallow bowl, sprinkle with Sichuan pepper and salt. Garnish.