Bun Bo Hue

Place beef marrow bones, pork hocks, and beef shank in a large stockpot covered with cold water. Bring to a rapid boil at 100C/212F for 10 minutes to force impurities to the surface.

Drain the pot completely and thoroughly rinse all the bones and meat under cold running tap water to remove any coagulated blood and scum.

Return the perfectly clean bones and meat to the large stockpot and add the 4000ml of fresh cold water. Bring the liquid up to a gentle simmer at 90C/194F.

Crush the thick bottom halves of the lemongrass stalks using the back of a chef knife to release their essential oils, then drop them into the simmering broth along with the whole peeled yellow onions.

Simmer the broth uncovered for 2 hours, actively skimming off any additional scum or excess fat that rises to the surface to ensure a clean tasting soup.

Remove the tender beef shank and pork hocks from the hot broth, submerge them briefly in a large bowl of ice water to halt the cooking process and prevent darkening, then transfer them to the refrigerator.

Continue simmering the remaining beef marrow bones and aromatics in the broth for an additional 2 hours to extract deep flavor and gelatin.

In a small frying pan, heat the neutral oil over medium heat and fry the annatto seeds for 2 minutes until the oil turns a deep crimson, then strain the hot liquid through a fine mesh strainer and discard the spent seeds.

Return the strained red annatto oil to the frying pan and saute the minced lemongrass, shallots, garlic, and chili flakes over medium heat until highly fragrant and caramelized.

Mix the fermented shrimp paste with a ladle of hot broth in a small bowl, stirring until completely dissolved to prevent clumping, then pour this mixture and the cooked chili aromatics into the main broth pot.

Season the broth with the rock sugar, fish sauce, and kosher salt. Reduce the heat to low, maintaining the finished broth at a hot 80C/176F until serving.

Thinly slice the completely cooled beef shank into even medallions, and separate the pork hocks into manageable bite-sized pieces using a chef knife and cutting board.

Boil the thick round rice noodles in a separate medium pot of rapidly boiling water at 100C/212F until tender with a slight chewy resistance, about 10 minutes, then drain in a fine mesh strainer.

Plate the soup by dividing the freshly cooked noodles equally into large serving bowls and arranging the sliced beef shank and pork hocks neatly on top.

Assemble the final dish by ladling the hot, intensely seasoned broth over the noodles and meat, ensuring each bowl catches a generous slick of the red chili oil from the surface of the pot.

Serve the steaming bowls immediately alongside a communal platter of shaved banana blossom, lime wedges, cilantro, scallions, mint, and Thai basil for guests to customize their own portions.