Season and sear the oxtail

• Pat the oxtail dry and season with salt, black pepper and brown sugar.
• Heat the oil in a stockpot and sear the oxtail on all sides until deeply browned.
• Set the oxtail aside.

Toast the whole spices

• In a dry frying pan, toast the cinnamon stick, star anise, coriander seeds and, if using, the clove and cardamom until fragrant.

Char the aromatics

• Char the onion, ginger, garlic and shallot in the frying pan until blackened at the edges.

Simmer the broth

• Return the oxtail to the stockpot with the toasted spices, charred aromatics and beef broth.
• Bring to a boil, then lower the heat and simmer gently, skimming the surface regularly, until the oxtail is tender.

Season the broth

• Strain the broth and discard the aromatics and spices.
• Stir in the fish sauce and hoisin sauce, then taste and adjust the seasoning.

Cook the noodles

• Soak or boil the rice noodles according to the package instructions, then drain.

Assemble and serve

• Divide the noodles among bowls and top with the oxtail.
• Ladle the hot broth over the top.
• Serve with cilantro, lime wedges and, if using, Thai basil, jalapeño and bean sprouts.