Prepare the pho broth: Place onions and ginger on cooking grate (on an open flame a gas stove) and let skin burn. Remove when fragrant. Under warm water, remove charred onion skin and discard blackened bits on the ginger with a knife.

Place bones in a stockpot, add water and bring to boil for a few mins. Dump bones and water into sink and rinse bones with warm water to remove impurities. Clean stockpot and return bones.

Add 6 litres of water to pot, bring to boil over high heat, then lower flame to gently simmer. Use ladle to skim any scum that rises to surface. Add remaining broth ingredients and cook meat, uncovered, for 1 1/2 hrs.

Remove cooked meat and place in bowl of cold water for 10 mins. After draining and cooling the meat, refrigerate it. Allow broth to continue simmering for around 3 hrs.

Strain the pho broth and use ladle to skim as much fat from top of the pho broth. Adjust flavour with additional salt, fish sauce and yellow rock sugar.

Prepare the noodles and garnishing: Fill large saucepan with water and bring to boil. Blanch noodles for about 10-20 seconds and arrange into bowls.

Then, blanch bean sprouts for 30 seconds. Drain and add to the garnish plate.

Place slices of cooked meat atop noodles. Garnish with onion, scallion and chopped cilantro.

Ladle in broth and serve.