Pat the green beans dry with paper towels to prevent them from splattering.

Heat 2 tablespoons vegetable oil in a large nonstick skillet over medium-high heat until hot. Add the green beans and a pinch of salt. Stir to coat well with oil. Spread the beans to prevent them from overlapping, as much as possible. Flip every 15 seconds or so. Cook and stir until some of the surface is brown and withered, and the green beans just start to turn soft, 6 to 8 minutes. If you prefer a softer texture, wait until most of the surfaces have charred, 10 to 12 minutes. Turn to medium heat if the pan starts to smoke too much. Transfer the green beans to a plate and set aside.

Add the remaining 1 tablespoon oil, ground pork, pickled mustard greens, and the ground Sichuan peppercorns. Cook and chop the pork to separate it into small pieces, while mixing with the rest of the ingredients.

When the surface of the pork has cooked, add the dried chili pepper, garlic, and ginger. Stir a few seconds to release the fragrance. Add back the green beans. Swirl in the Shaoxing wine, light soy sauce, and sugar. Cook and stir until the sauce is mostly absorbed, about 1 to 2 minutes.

Turn to low heat and carefully taste a green bean with some pork. Adjust seasoning by adding more salt, if needed. Transfer everything to a plate. Serve hot as a side dish or one of the main dishes of a multi-course meal.