Heat the vegetable oil in a wok or skillet over medium-high heat. Add the ground meat and cook until browned, breaking it apart as it cooks.
Add the minced garlic to the pan, stir-frying until fragrant. Lowe the heat, stir in the doubanjiang, preserved black beans, and chili flakes. Continue stir-frying until the oil turns a bright red color.
Pour the Shaoxing wine along the side of the wok and cook until the liquid evaporates. Then, add water or chicken stock. Season with soy sauce, sugar, and a pinch of salt as needed.
Drain the tofu and carefully add it to the pan. Use the back of your spatula to gently push the tofu, ensuring it doesn’t break. Turn to low heat and simmer for 5 minutes, allowing the tofu to absorb the sauce.
Mix cornstarch and water until smooth. Pour the mixture into the wok in two to three batches, letting it bubble before adding the next batch. Stir gently to thicken the sauce.
Stir in the chopped garlic sprout or green onion. Gently mix together.
Plate it up. Sprinkle with additional ground Sichuan peppercorn for an extra kick.