Place the tapioca starch in a large mixing bowl. Pour in 3/4 cup boiling water (about 200 ml) and mix well. Add a little cooking oil and knead until you have a smooth, elastic dough.

Divide the dough into 4 portions. Roll each portion out thinly. Dust with a little dry starch, stack 2-3 layers, then cut into noodle strips.

Rinse the pork bones and simmer them in 4 1/4 cups water (about 1 liter) with a pinch of salt, a little MSG, fish sauce, and sliced shallots. Peel the shrimp and lightly crush them with shallots and a pinch of salt. Heat a pan with a little oil, sauté shallots and chili powder until fragrant, then add the shrimp and stir-fry until cooked. Add the shrimp to the pork bone broth.

Bring the broth to a boil, then add the tapioca noodles. Gently stir with chopsticks to separate the noodles. Cook until the noodles are done, then season to taste.

Cut the crab cake into bite-sized pieces and add to the soup. Ladle the soup into bowls and top with black pepper, green onions, and cilantro for extra flavor.