Step 1

Place the beef bones, water, onion, ginger, cloves, star anise, cinnamon, cardamom and coriander seeds in a large saucepan and place over high heat. Bring to the boil. Reduce heat to low and cook, skimming surface occasionally of any fat with a metal spoon, for 3 hours or until liquid reduces by a quarter. Remove and reserve any meat from the bones. Strain the stock through a sieve and discard remaining solids.

Step 2

Place the soup over high heat and bring to a simmer. Add the fish sauce and lime juice and stir to combine. Taste and season with salt, pepper, fish sauce and lime juice.

Step 3

Meanwhile, place the noodles in a large heatproof bowl and pour over plenty of boiling water. Set aside for 5 minutes to soak. Drain well. Divide noodles and reserved beef evenly among serving bowls. Top with sliced beef. Pour the hot soup evenly among each serving bowl. Top with bean sprouts, mint, coriander and chilli. Serve immediately with lime wedges, if desired.