Bún Bò Huế

Method

1. Parboil the beef shank and pork bones in water for 10 minutes, then drain, rinse thoroughly and scrub the pot.
2. Return the meat and bones to the clean pot with the 5 qt (4.7 L) water, the bruised lemongrass and the halved onion. Bring to a bare simmer.
3. Simmer gently, skimming for the first 30 minutes, for 2 hours, until the shank is tender.
4. Lift out the beef shank, cool it, and refrigerate. Continue simmering the bones a further 45 minutes.
5. Make the chilli oil: warm the oil with the annatto seeds over low heat until the oil turns deep orange-red, 2–3 minutes; strain out and discard the seeds. Return the oil to the pan, add the shallots, garlic and minced lemongrass and cook until fragrant, then stir in the chilli flakes and remove from the heat.
6. Strain the broth into a clean pot. Discard the bones and spent lemongrass.
7. Let the shrimp paste mixture settle, then pour the liquid into the broth, leaving the grit behind. Add the fish sauce, sugar and salt. Simmer 10 minutes and taste — it should be salty, faintly funky and strongly lemongrass-scented.
8. Stir about half the chilli oil into the broth; reserve the rest for the table.
9. Cook the noodles according to type — fresh need 1–2 minutes, dried 8–10 — then drain and divide between six deep bowls.
10. Slice the cooled beef shank thinly across the grain. Lay it over the noodles with the sliced sausage.
11. Ladle over the boiling broth. Top with red onion, scallion and chopped herbs.
12. Serve with the banana blossom, bean sprouts, lime and chilli on a shared platter, and the remaining chilli oil in a small bowl.