Pour in a pot 7 cups of water and 3 cups of chicken broth. Place the hen pieces, onion, leeks, yellow chilli paste, celery, ginger, garlic, and carrots in the pot. Slowly bring to a simmer over medium heat. Skim off the foam which forms on top, and cook until broth becomes golden, or for about 2hrs.

Remove the hen pieces into a plate, and reserve them. Strain the broth into another pot, and discard the vegetables. Pour noodles, potatoes, salt and pepper to the broth, and bring to a boil over low-medium heat for about 15mins.

Add back the hen pieces, hard-boiled eggs, and scallions (on top). Serve and divide the soup between 5 bowls.