Authentic Vietnamese Beef Noodle Soup (Pho Bo)

Place 2kg beef marrow bones into a stockpot filled with 3L water over high heat. Bring to a rolling boil and simmer for 5 to 10 minutes until impurities and thick scum float to the surface.

Pour out the boiled water with impurities into the sink, transfer bones to a colander, and rinse them thoroughly under cold running water until clean of gray scum.

Transfer washed bones into a washed large stockpot. Pour in 5.5L fresh cold water, add 1 tbsp salt, 1 tbsp sugar, 1 peeled whole onion, and 500g beef brisket. Bring to a boil, then reduce heat to medium-low and simmer uncovered for 1 to 2 hours, skimming surface foam occasionally.

Slice 2 pieces of unpeeled ginger into thick slices. Cut 1 whole onion in half.

Place ginger slices, 3 star anise, 2 cinnamon sticks, 3 black cardamoms, and 2 onion halves directly on stove plate over medium-high heat. Char for 5 to 8 minutes, flipping with chopsticks until charred, blackened on surfaces, and aromatic.

Stuff charred star anise, cinnamon sticks, and black cardamoms into a spice filter bag or cheesecloth bag.

Peel burnt outer skin off charred onion halves. Scrape off blackened burnt parts from charred ginger slices and onion halves using a knife edge.

Add the spice filter bag, cleaned charred ginger slices, and charred onion halves into the simmering broth pot. Simmer gently uncovered over low heat for another 1 to 2 hours until beef brisket is tender.

Remove tender cooked beef brisket from boiling broth using chopsticks and submerge immediately into a bowl of cold water for 10 minutes. This prevents beef from turning dark and drying out.

Ladle out cooked onion halves from broth so they don't break apart and cloud the soup. Stir in 2 tbsp fish sauce, 1 tbsp seasoning powder, 1 tsp salt, and 1 tsp sugar to final taste. Continue simmering broth on low heat.

Remove cooled beef brisket from ice water, pat dry, and slice crosswise into thin bite-sized slices.

Slice 300g fresh beef fillet paper-thin for rare beef Pho (Pho Tai). Store cold until serving.

Slice 1 yellow onion paper-thin. Transfer onion slices to a bowl of ice cold water and soak for 30 minutes to reduce pungent raw sharpness and make them extra crisp.

Trim off white bulb heads of 4 spring onions and keep whole for blanching. Finely chop green stalk portions. Wash 50g Thai basil leaves and 30g sawtooth herb leaves in cold water, then drain.

Place 200g bean sprouts in hot boiling water for 10 seconds to blanch lightly, then drain completely into a strainer.

Soak 1kg dried flat rice noodles in cold water until softened (approx. 10 minutes). Portion hydrated noodles into a mesh noodle strainer and dip into a pot of boiling water for 10 to 20 seconds until chewy and tender. Rinse briefly under cold tap water, then flash dip in hot water so strands separate cleanly without sticking.

Place cooked rice noodles into serving bowls until 1/3 full. Layer sliced cooked brisket (and raw beef slices for Pho Tai), blanched spring onion bulbs, sliced soaked paper-thin yellow onions, and finely chopped green spring onions over noodles. Dust with 1 tsp ground black pepper, then ladle boiling broth over to submerge meat and noodles. Serve hot alongside lime wedges, blanched bean sprouts, Thai basil, sawtooth herbs, hoisin sauce, and sriracha.