Heat the vegetable oil in a frypan. Add garlic and ginger, fry until fragrant (around 30 secs to 1 minute). Add the pork mince and fry until browned. For crispier pork, keep cooking until darker. Add doubanjiang, soy sauce and sake, and cook on low-medium heat until the liquid has fully absorbed.
1.5 tbsp soy sauce, 1 tbsp vegetable oil, 200 g pork mince, 1.5 tsp garlic, 1.5 tsp ginger, 1 tbsp doubanjiang, 2 tsp sake, 1 tbsp soy sauce