Smash the garlic, black peppercorns and coriander root with a mortar and pestle. Rub this paste all over the pork ribs and place in a pot with 1 litre of water. Bring the pot a simmer and continue to cook.
Meanwhile, rub the salt into the sliced bamboo shoot. Place in another pot with plenty of water to cover the bamboo shoot and then some. Bring to a boil and boil for 5 minutes. Strain the bamboo shoot and discard the water. Add the bamboo shoot to the pork rib soup.
Cook the soup until the ribs are tender and season with fish sauce.