To begin, prepare the broth by boiling 4-5 cups of water in a large pot. Blanch the beef shank and pork hock in boiling water for 3-4 minutes to remove impurities, then rinse the meat under cold water. This ensures a clear, flavourful broth.

In a large pot, add the blanched beef shank, pork hock, smashed lemongrass, shallots, ginger, and garlic. Pour in enough water to cover the ingredients, about 4-5 cups. Bring to a boil over high heat, then reduce to low, allowing it to simmer gently.

After simmering for 30 minutes, add the shrimp paste to the broth. Stir well to dissolve, as this ingredient brings a signature depth of flavour to Bún Bò Huế. Add the fish sauce and let the broth continue simmering for 1-1.5 hours until the meat is tender.

While the broth simmers, prepare the noodles according to package instructions. Drain well and set aside. If using pork blood cubes, add them to the broth for the last 20 minutes of cooking, allowing them to heat through.

Once the meat is tender, remove it from the broth and slice it thinly. Strain the broth to remove any solids, ensuring a clear soup. Return the broth to the pot and taste, adjusting seasoning with more fish sauce or chili oil if desired.

To serve, divide the cooked noodles into bowls. Place slices of beef shank, pork hock, and brisket (if using) on top of each bowl, along with a few pork blood cubes for those who prefer a traditional touch.

Ladle the hot, aromatic broth over each bowl, covering the noodles and meat. Top each bowl with thinly sliced white onion, fresh herbs, green onions, and sliced red chili for added flavour and freshness.

Serve the Bún Bò Huế immediately, accompanied by lime wedges for added tang. Encourage guests to add fresh herbs, chili slices, and extra fish sauce to their bowls as desired, allowing them to adjust the spice and flavour to their preference.