Parboil the bones: cover with cold water, boil hard 5 minutes, drain and rinse. Scrub the pot.

Char the onion and ginger directly over a flame or under the broiler until fragrant and blackened.

Dry-toast the spices 1-2 minutes until aromatic, then tie in a spice bag.

Simmer bones in 5 L water with brisket, charred aromatics and spice bag at a bare simmer for 3 hours, skimming foam. Remove brisket at 1.5 hours and slice once cool.

Season the broth with fish sauce, rock sugar and salt to taste — savory and aromatic, not salty.

Cook noodles per package, divide into bowls, top with raw beef slices and brisket, then ladle boiling broth over to cook the raw beef. Serve with herbs and condiments.