Japanese Mapo Tofu Udon Noodles

Name: Japanese Mapo Tofu Udon Noodles
Ingredients: 300 g pork mince; 100 g firm tofu (cubed); 1 udon noodles ((if frozen, cook according to packet directions first)); 2 tsp garlic (finely chopped or minced); 1 tsp ginger (finely chopped or minced); 3 tbsp soy sauce; 2 tbsp doubanjiang (Chinese black bean sauce); 2 tbsp white miso paste; 2 tbsp mirin; 1 tsp oyster sauce; 1 tsp cornstarch / cornflour; ¼ cup cold water; 1 tsp sesame oil; 1 tbsp vegetable oil (for cooking); 1 spring onion / green onion (optional garnish)