To begin, rinse the beef shank thoroughly under cold water to remove any loose bone fragments. Pat dry with a clean kitchen towel. Move to initial simmering.

Place the beef shank in a large pot, cover with water and bring to a boil for 10 minutes. This draws out impurities. Discard the water and rinse the beef and pot before continuing.

Return the beef to the cleaned pot. Add 2.5 litres of fresh water, onion, garlic, peppercorns and bay leaves. Bring to a boil over medium heat, then reduce to a gentle simmer. Skim off any foam that rises to keep the broth clear. Transition to long simmering.

Cover and simmer gently for 2 to 2.5 hours until the meat is very tender and the marrow is soft. Add more water if needed to keep the shanks submerged. Move to seasoning.

Add fish sauce and salt to taste. The broth should be savoury with a hint of natural sweetness from the beef. Continue to the vegetable additions.

Place the corn, potatoes and carrots into the pot. Simmer for 20 minutes or until these vegetables begin to soften. Proceed to adding leafy vegetables.

Add the cabbage quarters and pak choi. Cook for 5 to 7 minutes until just tender. Avoid overcooking to retain texture and colour. Move to finishing.

Taste the broth and adjust seasoning with more fish sauce or a pinch of salt. The broth should taste balanced before serving. Transition to final plating.

Ladle the hot broth, vegetables and beef into bowls. Serve immediately with rice. Presentation tip: Offer fish sauce with calamansi on the side for extra brightness.