Combine the ground pork with the salt, pepper, and cornstarch. Marinate the pork for 15 minutes.
While the pork is marinating, prepare the remaining ingredients. In a small bowl, combine the chicken broth, dark and light soy sauce, vinegar, and sugar. Whisk in the cornstarch.
Cut the eggplant into 1-inch squares. Mince the garlic.
Heat the wok over medium-high to high heat. Add 2 tablespoons of oil. When the oil is hot, add the eggplant. Stir-fry the eggplant until it is softened (about 5 minutes). Remove and drain on paper towels.
Add 2 tablespoons oil to the wok. When the oil is hot, add the garlic and bean sauce. Stir-fry until aromatic. Add the ground pork. Stir-fry until it changes colour, using cooking chopsticks or a wooden spoon to separate the individual pieces.
Push the pork up to the sides of the wok. Add the sauce in the middle and bring to a boil, stirring quickly to thicken. Add the eggplant slices and the chilli paste. Cook for a few more minutes and stir in the sesame oil. Serve hot.