Combine the pork with all of the marinade ingredients, and let sit for at least 15 minutes. Drain the soft tofu, and cut into large squares, about 1 - 1.5 inches across.
Heat 1 tablespoon of canola oil in a large skillet over medium-high heat. When the oil is hot, add the garlic and ginger and about half the scallions and cook until fragrant, about 30 seconds. Add the pork with all of the marinade sauce and cook, stirring, until the pork is cooked through and no trace of pink remains, about 5 minutes. Scoop pork with a slotted spoon into a separate bowl and set aside, leaving behind the sauce and juices in the pan.
Add the tofu cubes into the skillet, along with the rest of the scallions and the regular soy sauce. Add the chili black bean sauce and the chili oil, if using. Cook until the tofu is slightly crumbling at the edges, about 3 minutes. Tofu is perfectly fine to eat right out of the package, so you're just heating it up here.
Add the pork back into the pot and stir to combine. Taste and add more sauce, chili oil, or Szechuan peppercorns, if desired.