Among Vietnamese noodle soups, bún bò Huế is second only to phở in popularity. But while phở is delicate and nuanced, bún bò is earthy and spicy, characteristic of central Viet cooking and the elegant yet rustic table of Hue, the former imperial capital. And although its name suggests an all-beef affair, the soup actually combines beef and pork.
To make great bún bò Huế I heed the advice of family friend Mrs. Nha, a Hue native who insists that the broth be made with beef bones, not the pork bones widely used today. From my mom, I learned to sauté the onion and boneless meat for a deeply flavored broth. On my own, I discovered that simmering the annatto (seeds from the achiote tree) in the broth yields a nice rich color. (Most cooks fry the seeds in oil to release their color and then add the oil to the finished broth.)
Shop for the various meats you need at a Viet or Chinese market, where you will find beef shank (shin) in long pieces, boneless pork leg with a layer of fat and skin, and slices of pork hock, often prepackaged in plastic foam trays.
BUN BO HUE
For the broth:
4 pounds beef leg bones, cut into 2- to 3-inch pieces
1-½ pound boneless beef shank, halved crosswise
¾ pound boneless pork leg with skin and fat
2 tablespoons canola or other neutral oil
2 yellow onions, cut into 1-inch chunks
1 tablespoon annatto seeds
1 ½ pound pork hock, cut into ½-inch-thick pieces (8 pieces)
3 tablespoons fish sauce
1-ounce yellow rock sugar (about 1-inch chunk)
4 hefty stalks lemongrass, trimmed, cut into 3-inch lengths, and bruised
2 tablespoons fine shrimp sauce
For the chile-lemongrass mix:
5 tablespoons canola or other neutral oil
3 tablespoons dried red chile flakes
3 cloves garlic, minced
1 stalk lemongrass, trimmed and minced
1 tablespoon sugar
2 ½ teaspoons fish sauce
For the bowls:
Cooked beef and pork from the broth
2 packages (14 ounces each) large or extra-large dried round rice noodles, cooked in boiling water for 10 to 15 minutes, drained, and flushed with cold water
1 yellow onion, sliced paper thin, soaked in cold water to cover for 30 minutes, and drained
2–3 scallions, green parts only, thinly sliced
⅓ cup chopped fresh Vietnamese coriander or cilantro leaves
For the garnishes:
2 or 3 limes, cut into wedges
12 sprigs mint
2–3 Thai or serrano chiles, thinly sliced
Leaves from 1 head romaine lettuce, halved lengthwise and cut crosswise into ¼-inch-wide ribbons (optional)
3 cups bean sprouts (about ½ pound) (optional)
1 cup thinly sliced banana-blossom bracts (leaves), soaked in acidulated water, massaged with warm water, and drained well (optional)
Spoonful of fine shrimp sauce (optional)
Broth and chile-lemongrass mix:
To achieve a clear broth, first parboil and rinse the beef bones. Put them in a stockpot (about 12-quart capacity) and add cold water to cover. Bring to a boil over high heat and boil for 2–3 minutes to release the impurities. Dump the bones and water into the sink, and then rinse the bones with water to wash off any residue. Set the bones aside. Scrub the stockpot, dry it, and set aside.
Lightly season the beef shank and the pork leg with salt and pepper and set aside. Add the oil to the stockpot and heat over medium-high heat. Add the onions and cook until fragrant, about 1 minute. Add the annatto and stir to release its color. When the onion is yellow-orange, push it to the side and add the beef shank and pork leg. Briefly sear the meat to lightly brown it.
Pour in the water and add the reserved bones and the pork hock. Bring to a boil over high heat and lower the heat to a gentle simmer. Use a ladle or large shallow spoon to skim off any scum that rises to the top. Add 1 ½ tablespoons salt, the fish sauce, rock sugar, and lemongrass. Simmer gently, uncovered, for 1 hour.
Transfer the pork leg and hock to a bowl of cold water to cover. Let soak for 10 minutes to prevent it from drying out and turning dark. Drain the meat, set aside on a plate to cool completely, then cover with plastic wrap and refrigerate. Meanwhile, simmer the broth for 1 additional hour after removing the pork, for a total of 2 hours.
When the broth is done, remove the beef shank, soak it in cold water as you did the leg and hock, and then drain, cool, and store with the pork. Strain the broth through a fine-mesh sieve (or a coarse-mesh sieve lined with cheesecloth) positioned over a pot. Discard the solids. Use a ladle to skim as much fat from the top of the broth as you like. (Or let cool, refrigerate overnight, lift off the solidified fat, and reheat before continuing.)
To make the chile-lemongrass mix, put the oil, chile flakes, garlic, and lemongrass in a small saucepan and bring to a gentle simmer over low heat. Let bubble and sizzle for 5 minutes, swirling or stirring occasionally. Remove from the heat and stir in the sugar and fish sauce. Transfer to a small serving bowl and let cool.
To finish the broth, scoop out a little into a cup, stir the shrimp sauce into the cup, and pour the mixture through a fine-mesh sieve into the broth. Depending on your taste, stir in one-fourth to one-half of the chile-lemongrass mix, saving the rest for serving at the table. Taste and adjust the flavor with additional salt, if necessary. There should be about 4 quarts (16 cups) broth.
Bowls and garnishes:
To assemble the bowls, reheat the noodles, fill a large pot with water and bring to a rolling boil. Meanwhile, cut the beef and pork leg across the grain into slices about 1/16-inch thick. For the best results, make sure they are cold. Set the beef and pork leg aside. Put the pork hock pieces in the broth. Have the noodles, yellow onion, scallions, and Vietnamese coriander ready. Arrange the garnishes on a plate or put them in small dishes and put on the table. To ensure good timing, bring the broth to a simmer over medium heat while you are assembling the bowls.
When the water has reached a boil, place a portion of the noodles on a vertical-handle strainer (or mesh sieve) and dunk the noodles in the water. After 5 to 10 seconds, pull the strainer from the water, letting the water drain back into the pot. Empty the noodles into a bowl and repeat with the remaining portions while proceeding to assemble each bowl as the noodles are added.
Top each bowl of noodles with the beef and pork, arranging the slices flat. Place a mound of yellow onion in the center and then shower some scallion and Vietnamese coriander on top. Bring the broth to a rolling boil. Ladle 2 cups broth into each bowl, distributing evenly to warm the ingredients and including a piece of pork hock with each portion. Serve immediately with the garnishes and the remaining chile-lemongrass mix.
Note on banana-blossom bracts:
You will find giant burgundy teardrop-shaped fresh banana blossoms (which are technically buds) in the produce section of Chinese and Vietnamese markets. Select one that feels firm and solid (not spongy) and has a tightly closed tip. The smaller the better because there is less astringency in the bracts (petal-like leaves) and flowers. The blossoms are at their peak in the summer. Simply remove some of the bracts, stack them, and then slice them. Soak for 10 minutes in 1 tablespoon distilled white vinegar and water to cover. Then massage and drain them.
Reprinted with permission from Into the Vietnamese Kitchen: Treasured Foodways, Modern Flavors by Andrea Nguyen, ©2006. Published by Ten Speed Press, an imprint of Penguin Random House.