In a pan, heat 2 teaspoons of the sesame oil over medium-high. Add spring onion, pork and garlic. Cook, stirring, for 2 minutes. Add eggplant, stock, soy sauce, sweet chilli sauce, ginger and 1 cup water and bring to a simmer. Reduce heat and simmer gently for 15 minutes, until eggplant is soft and collapsing.