Vietnamese Lau Broth
Some cooks make Lau with water instead of beef broth. Try this version, and serve the broth in small portions as a hot and sour soup.
Slice the tenderloin in paper-thin slices and arrange on 2 serving platters. Thinly slice onion and toss slices in 2 tablespoons rice vinegar. Drizzle sesame oil over beef and sprinkle with fresh-ground black pepper. Drain vinegar from the onions and arrange over the beef.
In a saucepan, combine 1 cup rice vinegar, beef broth, ginger, garlic, lemongrass, salt, and sugar. Bring to a boil, then reduce heat and simmer for 10 minutes. Pour broth into 1 or more fondue pots, then place pots over heating sources. Place beef platters near pots and have guests cook beef in the hot broth.
Soak rice noodles in hot water for 10 minutes to soften. When beef has been cooked, drop noodles in the hot broth until cooked. Sprinkle with black pepper and ladle into bowls for guests. Pass peanuts as garnish.
Food to Go
Hot pot, or Lau, is very popular in Vietnam, both as a street food and as upscale restaurant fare. Feel free to vary your Lau to include seafood, chicken, tofu, and a range of vegetables.