If it is difficult to get those noodles, then use "Barilla Capellini No. 1". While cooking them, just add 1 tbsp of baking soda in the boiling water (1 tbsp baking soda per 1 liter of water). The pasta will turn more Ramen-like, and that's all you need to do. It is quite helpful when you are busy :-)
1. Prepare the meat : In a large stockpot, place the chicken (or the pork) and green parts of leek (optional). Fill with enough water (at least 900ml) to cover the meat, bring to a boil and then reduce the heat to low. Cover the pot and simmer for about 15 to 20 mins (depending on the thickness of the meat chunks), make sure the meat is well cooked. You can add water in the process if necessary.
2. Remove the meat from the water and drain, then slice it thinly. Keep the water in which you boiled the chicken (or pork) to make the soup - you'll need about 800ml or more. Set aside both.
NOTE : If you use pork, you should now fry it with 1 tbsp sesame oil until light brown. It will taste better.
3. In a cooking pot, heat 1 tbsp vegetable oil and fry garlic and ginger until fragrant. Add leek and fry until wilted. Add sesame paste and white miso, continue cooking for about 2 minutes, stirring constantly. Add the water from step #2 and soy milk.
4. Once it boils, add the ingredient A to season the soup and simmer for about 5 to 10 minutes.
Now we fix it all together :
5. Boil the noodles according to the package directions, drain the noodles very well and divide the noodle into four serving bowl. Pour the hot soup over the noodle. Top with the meat slices.