Marinate the pork with the char siu sauce, set aside for 15 mins
Cut up garlic, ginger and spring onion. In a pot put in 4 cups of stock with 3 cups water. Add the fish sauce and soy sauce and on a medium heat bring the stock to a simmer. Add the noodles & bok choy and cook for 3-5 mins. Remove from heat and put a lid on to stay warm.
Meantime in a hot pan add 1 tbsp peanut oil and cook pork medallions until cooked about 3-4 mins or till cooked and cover them and allow to rest for 2 mins. Add last tbsp. of oil and cook ginger, garlic and white spring onion for 1 min then remove from heat.
Serve the stock in deep bowls. Add the garlic, ginger & white spring onion to stock mix. Scoop some noodles and ½ the bok choy into the bowl. Slice pork and put into the bowl, then top with the shredded green onion.