I’m back with more soup! My youngest daughter and I are kindred spirits in this way. We could eat soup for every meal every day and be pretty happy. It must be the Vietnamese heritage.
So when the weather got cold again, I automatically went into soup making mode and arrived at this lemongrass beef and noodle soup. It’s adapted from another traditional Vietnamese soup called bún bò huế. For that soup, you start with a lemongrass beef stock and add paprika, shrimp paste, chiles and more lemongrass. The flavor can be pretty intense and you really have to be in the mood for spicy. I decided I wanted something more subtle. So I nixed the extra spices and focused on making a fragrant broth of beef and lemongrass. The result is something akin to broth for pho, the other well known Vietnamese noodle soup. However, this broth has its own personality that is lighter and brighter due to the lemongrass. Honestly, I could drink mugs of the broth and feel pretty satisfied.
However, the family wanted a proper meal so, for serving, I added the usual standbys for a traditional Vietnamese soup – flat rice noodles, thinly sliced onions, hoisin sauce, and Sriracha. If you really want to go old-school, you can dip the slices of beef in a mixture of lime juice, salt, and pepper. It is how my father likes to eat his bún bò huế. I must admit I never could get into the bracing hit of the salt and lime juice combination but I put it out there in case you’re wondering why I have a dish of salt and pepper and some lime wedges in these photos.
For the soup stock
- 2 tablespoons fish sauce, plus more to taste
- 2 teaspoons kosher salt
- 2 teaspoons black pepper
- 1 1/2 pounds beef round, cut in half lengthwise
- 3 1/2–4 pounds beef bones
- 8 cups low-sodium chicken broth
- 6 cups water
- 2–3 fresh lemongrass stalks, cut into large pieces and lightly smashed
- 1 large yellow onion, peeled and quartered
- 1 tablespoon granulated sugar
- 8 ounces dried flat rice noodles (see Notes)
- Thinly sliced onions
- Chopped fresh cilantro
- Chopped fresh green onions
Other optional garnishes
- Hoisin sauce
- Asian fish sauce
- Hot sauce such as Sriracha sauce
- In a small bowl, mix together the fish sauce, salt, and pepper. Place the beef round pieces in a medium bowl and rub the beef all over with the marinade. Cover the bowl and let the beef marinate in the refrigerator for at least 2 hours.
- Place the beef bones and marinated beef round in a large stock pot. Pour in chicken broth and water. Bring the mixture to a boil over medium-high heat, skimming out the impurities and froth. Reduce heat to low. Add the lemongrass, onion, and sugar. Partially cover the pot and simmer until the beef round is tender, about 1 1/2 hours. Using tongs, remove the beef round from the stockpot and transfer it to a storage container and place in the refrigerator.
- Continue simmering the soup stock for 2-3 more hours, skimming out the impurities and froth as needed.
- Strain the broth through a fine-mesh strainer into a new pot. Let the soup settle for a few minutes and then skim as much fat as possible off the top (see Notes). Season with fish sauce and salt to taste.
- Cook the noodles in a large saucepan of boiling water until just tender, 6 to 8 minutes. Drain the noodles and rinse well until the water runs clear. Divide the noodles among serving bowls. Top the noodles with some thinly sliced onions.
- Remove the beef round from the refrigerator and cut it into thin slices. Place the slices on top of noodles and onions, dividing the beef equally among the serving bowls.
- Bring the strained broth to a boil over high heat.
- Ladle the boiling broth over the sliced beef in each bowl. Top with some sliced green onions and cilantro. Add other garnishes as desired.
Dried flat rice noodles are sometimes labeled as Banh Pho or Pad Thai noodles. They often come in different widths. For this soup, I recommend the small or medium width.
The most effective way to defat the stock is to refrigerate it, uncovered, until it is well chilled and the fat has solidified on top. Lift off and discard the fat.