I have made a large pot of Chinese braised beef shank (Lu Niurou) and I find a shortcut to assemble a beef shank noodle soup. Super easy if you have a pot of braised beef shank with the first time master stock (卤水).

The assembling idea comes from very famous Taiwanese beef shank noodles, with a very unique ingredients: pickled mustard green. Pickled mustard green  (酸菜) is a very popular side ingredients in Mainland China and also Taiwan area. It provides crunchy texture when using as topping like Gua Bao and provides unique sour and umami when using in soups, like Suan Cai fish slices.

Ingredients you will need

100g braised beef shank
2 Bok Choy
2 serving noodles (either fresh or dried, I use fresh udon this time)
2 green onions, finely chopped
1 small bunch of coriander, finely chopped
For beef stock
500g oxtail+ 250g back bones+ 250g chicken bones
salt to taste
1 green onion
1 thumb ginger
2 star anise
1 small piece of Chinese cinnamon
2 bay leaves
1/4 teaspoon Sichuan peppercorn (must)
4 cloves
2L to 2.5 L water

Steps:

1. Remove the blood waters: add all the bones and meat in a large pot, pour in enough water to cover, add green onion and 4 slices of ginger and then bring to a boiling. Transfer out and clean.
2. Soak all the spices with around 1/2 cup boiling hot water for 10 minutes and then wrap all of them with a glaze bag and seal with cotton lines.
3. Add all the bones and beef shank, scallion whites and spiced wrapped in the glaze bag. Pour around 2L to 2.5 L water (separately for high pressure cooker and cast iron soup pot). Bring to boil and simmer for around 1.5 to 2 hours.To begin assembling a wonderful beef noodle soup, get yourself a pot of beet stock.

4.Cut half of braised beef shank into thin slices and half of it to diced. Chop pickled mustard green and fry with oil until aroma.

Assemble the noodles:
In a serving bowl, mix 1 cup of beef stock with 1/2 cup of the master stock (卤水). Cook the noodles according to instructions and then blanch the Bok Choy and transfer them to the bowls. Top with fried mustard greens, green onion and coriander. Serve hot!

If the soup base is not enough to cover the noodles, add more soup. The master stock should be salty enough, otherwise add a small pinch of salt to taste.