Rinse the black beans to remove any grit. In a small bowl, mash the black beans with the back of a spoon.
In a medium bowl, combine together the black beans, stock, chili bean sauce, rice wine, soy sauce, sesame oil, sugar and Sichuan pepper. Set aside.
Heat a large skillet over high heat. Add oil and swirl to coat all sides. Add the ground pork and stir-fry for 2 minutes or until meat is brown and no longer pink.
Reduce heat to medium and then add the leek, garlic and ginger; stir-fry for 1 minute.
Give the sauce one last stir and then add to the pan. Bring the mixture to a boil and then gently add the tofu cubes, making sure not to move them around too much. Cook for 2 to 3 minutes or until tofu has completely absorbed the sauce.
Give the cornstarch mixture one last stir and then stir into the pan. Continue cooking until sauce has thickened. Sprinkle with chopped green onions.
Serve with steamed rice. Enjoy!