Pho Bo (Beef Pho Noodle Soup)

Make the beef broth: Roast the onion and ginger in an open flame until completely charred; cool. Remove the charred skin and rinse. Slice onions in quarters and ginger in half. In a large stockpot, place bones and cover with cold water. Boil over high heat for 2 to 3 minutes to allow impurities to be released. Discard the water and rinse the bones. Place bones in a clean, large stockpot and add 12 cups water. Bring to a boil then reduce to a simmer. Remove scum that rises to the surface. Add onion, ginger, and the rest of the ingredients for the broth. Simmer for 1 1/2 hours. Remove the beef brisket and set aside in the refrigerator. Continue simmering the bones for another 1 1/2 hours. Skim off any fat. Adjust seasoning if necessary with salt, fish sauce, and sugar. Strain using a strainer lined with cheesecloth. Place broth in a stockpot and keep hot.

Prepare noodles by soaking in water until soft as per package instructions. Blanch noodles for a few seconds in hot water, drain, then transfer to serving bowls. Blanch the rib eye or sirloin in the same water for a few seconds just until beef changes color from pink to brown.

Top noodles with the cooked beef brisket and rib eye or sirloin. Add steaming hot broth. Garnish with onion, leeks, and cilantro. Season with black pepper. Serve with blanched bean sprouts, Thai basil leaves, cilantro, bird's eye chili, and sliced lime, if desired.