Add 3 cups water (about 700 ml) to a pot. Add the cilantro roots and bring to a boil. Once boiling, add the carrot, onion, and mushroom. Cook for 15-20 minutes.

Remove the vegetables from the broth. Season the broth with the ingredients listed above, then add the pork and boil until cooked through.

Add the bánh canh noodles, pork, and fish cake to the bowl. Serve with lime and either pickled chili or chili oil. Don't forget these toppings!