Heat the Sichuan peppercorns in a dry frying pan over medium-high heat until just starting to smoke. Use a mortar and pestle to grind to a fine powder. Set aside for later. To prepare the tofu, carefully cut open the packet, drain away the liquid and tip the tofu out onto a cutting board. Cut the tofu into bite-sized cubes. Set aside for later. In a wok or large frying pan over high heat, add the oil. Then add the pork mince and cook, breaking up the meat for 2-3 minutes. Add the garlic and the ginger. Stir-fry for half a minute. Then add the douban jiang and chilli powder. Stir-fry until well combined. Now stir through the ground Sichuan pepper, chicken stock, soy sauce, dark soy sauce and sugar. 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 corn flour mixture. Now add the Sichuan peppercorn powder. Taste and season with extra salt or soy sauce if needed. Now gently add in the silken tofu to the pork. Drizzle with sesame oil and gently toss the tofu and pork together, trying not to break up the tofu too much. Divide your noodles among serving bowls. Top with the mapo tofu. Sprinkle with spring onions and serve. *NOTES – Douban jiang is a spicy fermented chilli bean paste. Find it at your Asian grocery store.