Step 1

Place a wire cooling rack over the flame of a burner, set to high heat. Place ginger and onions on the rack and turn it occasionally until the skin becomes slightly blackened on all sides. It will take about 10 to 15 minutes.

Step 2

Place the bones in a stockpot and immerse in cold water. Bring to a boil over high heat. Boil vigorously for 5 minutes to allow impurities to release from the bone. Tip the bones into a sink. When cool enough to handle, rinse the bones under running water and carefully remove any debris from them. Clean the stockpot, return the bones to the pot.

Step 3

Add just enough cold water to immerse the bones. Bring to boil over high heat, While the broth is boiling, skim off any impurities on the surface for 15 minutes to ensure a clean, clear broth, then reduce the heat to a low simmer. Add brisket, charred onions, ginger, star, anise, cinnamon, fennel, cloves, coriander, fish sauce, sugar, and salt.

Step 4

Gently simmer uncovered for 1 1/2 hours. When the brisket is tender, remove it from the broth and place it in cold water to cool. Drain and keep in the refrigerator for use later.

Step 5

Continue simmering for 3 1/2 hours, top up the water as necessary to just immerse the bones.

Step 6

Strain the broth through a fine strainer. Discard the bones and the spices. Adjust the final volume of the broth to 4 liters. Skim off the oil on the surface as much as possible. Season the broth with additional salt, fish sauce and rock sugar if desired.

Step 7

Blanch the rice noodles in boiling water for 20 seconds. Drain, then transfer back to the bowl. Place a few pieces of beef brisket and raw sirloin on top of the noodles. Bring the broth to rolling boil. Ladle the broth evenly over the raw meat and other ingredients.

Step 8

Garnish with spring onion and coriander to each bowl.

Step 9

Serve hot with some bean sprouts, basil, and lime.