Heat wok over a high flame until wisps of heat start to rise and add enough canola or peanut oil to deep-fry. Bring oil temperature to about 350°F (175°C) and deep-fry green beans until most of them have puckered skin. Do not brown them. Remove and drain on paper towel.

Remove all but 2 tablespoons oil from the wok. Reheat until hot and add pork, breaking it up into crumbles and cooking until it starts to brown. Add dried chili peppers, yacai, scallions, ginger and garlic and continue stir-frying. Add Shaoxing wine, soy sauce and sugar and cook until the pork bits are crispy.

Add back the green beans and stir-fry until well-mixed and hot. Add the sesame oil, give a stir, and plate.

Heat wok over a high flame until wisps of heat start to rise, then add 2 tablespoons oil. When hot, add green beans, stir-frying vigorously for about 2 minutes. Lower heat to medium and cook, stirring occasionally, for about 6 minutes. Remove and drain on paper towel.

Reheat wok until hot and add 2 tablespoons more oil. Add pork, breaking it up into crumbles and cooking just until pink disappears. Add yacai, scallions, ginger and garlic and continue stir-frying. Add Shaoxing wine, soy sauce and sugar and cook briefly. Do not brown.

Add back green beans, mix well, and lower heat to very low setting. You should hear a slight sizzle as the mixture cooks over the next couple of hours. Stir every 10 to 15 minutes to make sure pork isn't burning. Cook for about two hours. Add the sesame oil, give a stir, and plate.