In a large, dry, clean skillet or frying pan, toast the Szechuan peppercorns over medium-low heat, shaking the pan occasionally, until they are fragrant and beginning to darken in colour. Transfer the peppercorns to a bowl to cool. When completely cool, grind them in a spice grinder, blender, or mortar and pestle. Store in an airtight jar until ready to use.
Return the skillet or frying pan to the burner, this time over medium-high heat. When the pan is hot, add the peanut or canola oil and swirl to coat. Break up the ground pork over the hot oil and stir-fry, continuing to break up the pork into smaller and smaller pieces, until the pork is cooked all the way through and has browned and crisped up on the outside. Sprinkle the chili powder, garlic, ginger, and white sections of the green onions over the crisped pork and stir-fry until fragrant. Add the black bean chili sauce, water, and the Gochujang or Sriracha then stir together and bring to a gentle simmer, scraping the bottom of the pan to get up any delicious crispy bits that have clung to it. Gently stir in the tofu cubes and simmer until the sauce is thick and the tofu is hot all the way through. Sprinkle at least 1 teaspoon of the ground Szechuan peppercorns over the dish, stir, and taste. If you want to make the sauce hotter, add a bit more more Gochujang or Sriracha, taking care, though, because that also adds saltiness to the dish. If you need to tone down the saltiness, or your sauce is too thick, add a bit more water to thin it and return to the burner just until hot all the way through.