Huê´-Style Spicy Beef and Rice Noodle Soup (Bún Bò Huê´)
3 medium yellow onions, 2 cut into 1" dice,
1 thinly sliced
1 tbsp. annatto seeds
2 lbs. boneless beef shank (shin), halved
crosswise, tendon removed and discarded
1 lb. boneless pork leg, from the upper butt portion
Salt and freshly ground black pepper
4 lbs. beef bones, cut into 2" pieces,
boiled for 3 minutes
1 1⁄2 lbs. fresh pork hock, cut into 1⁄2" slices
3 tbsp. plus 2 1⁄2 tsp. Vietnamese fish sauce
5 trimmed stalks lemongrass, 4 cut into 3"
pieces, bruised;1 minced
1 1" chunk Chinese yellow rock sugar
3 tbsp. dried chile flakes
3 cloves garlic, minced
1 tsp. granulated sugar
2 tbsp. fine shrimp sauce
2 14-oz. packages large round bún (Vietnamese
rice noodles), boiled, then rinsed with cold water
1⁄3 cup chopped rau ra˘m (Vietnamese coriander)
3 scallions, green parts only, trimmed and thinly sliced
1. For the broth: Heat 2 tbsp. oil in a stockpot over medium-high heat. Add diced onions and cook for 2 minutes. Add annatto; cook until onions are yellow, 4–5 minutes. Season beef and pork leg with salt and pepper; push onions to side; add beef and pork. Sear meat for 4–5 minutes; add bones, hocks, and 5 quarts water. Bring to a boil; skim off and discard any scum. Add 3 tbsp. fish sauce, bruised lemongrass, and rock sugar; reduce heat and simmer for 1 hour. Transfer pork leg and hocks to a bowl of cold water; let soak for 10 minutes. Simmer broth for 1 hour more. Repeat soaking and draining with shank. Chill leg, hocks, and shank in refrigerator. Skim fat from broth; strain through a fine sieve.
2. Combine remaining oil, chile flakes, garlic, and minced lemongrass in a small pot over medium-low heat; gently simmer for 5 minutes. Remove from heat; stir in remaining fish sauce and granulated sugar. Set chile mixture aside.
3. Bring broth to a boil in a large pot. In a bowl, stir together 1 cup of broth with shrimp sauce; pour into pot through a fine sieve and stir in 1 1⁄2 tbsp. of chile mixture. Season to taste with salt. Divide noodles between 8 bowls. Cut beef and pork across the grain into 1⁄16"-thick slices; top each bowl with slices, followed by sliced onions, rau ra˘m, and scallions. Add hocks to broth; bring to a boil. Ladle 2 cups hot broth with some hock into each bowl. Serve with remaining chile mixture, mint sprigs, sliced thai chiles, and lime wedges, if you like.