Vietnamese Watercress Salad with Beef (Xa Lach Xoong Bo)

The whole dish turns on one moment: hot, just-seared beef landing on cool, crisp watercress, then a lime-and-fish-sauce dressing poured over while everything is still warm. Sear the beef a minute too long and it toughens; dress the greens too early and they wilt. Work fast, assemble at the table, and serve immediately — the contrast of hot beef and cool greens is the point, and it fades as it sits.

This is a home adaptation of a common Vietnamese salad preparation, not a claim of regional authenticity.

Ingredients

Serves 4.

• 1 lb (450 g) top sirloin or flank steak, sliced thin against the grain (about 1/4 inch)
• 2 bundles watercress (about 8 oz / 225 g), thick stems trimmed, washed very well and dried
• 1/2 small red onion, thinly sliced (soaking 10 minutes in cold water then draining takes the raw edge off — optional)
• 2 roma tomatoes, cut into wedges
• 1 tbsp neutral oil, plus more for searing
• 1/4 cup crushed roasted peanuts (optional garnish)
• 2 tbsp fried shallots (optional garnish)

Beef marinade

• 1 tbsp oyster sauce
• 1 tbsp fish sauce
• 1 tsp sugar
• 1 tsp minced garlic
• 1/2 tsp freshly ground black pepper
• 1 tbsp neutral oil

Dressing (lime-fish sauce vinaigrette)

• 3 tbsp fish sauce
• 2 tbsp fresh lime juice
• 2 tbsp sugar
• 3 tbsp water
• 1 small clove garlic, minced
• 1 Thai chile, sliced (optional)

Method

1. Prep the greens. Trim the watercress, wash thoroughly in several changes of water, and dry well — a salad spinner earns its keep here. Wet greens dilute the dressing. Use cultivated, food-grade watercress from a grocery store or market, not foraged. Arrange the watercress, red onion, and tomatoes on a serving platter.
2. Marinate the beef. Slice the steak thin against the grain (about 1/4 inch). Toss with all marinade ingredients and let sit 20 minutes at room temperature while you prep everything else.
3. Whisk the dressing. Combine the fish sauce, lime juice, sugar, and water, stirring until the sugar dissolves. Add the garlic and chile. Taste — it should be bright and balanced, not harsh.
4. Sear the beef. Heat a large skillet or wok over high heat with a thin film of oil until it just starts to smoke. Lay the beef in a single layer and cook about 2 minutes total, tossing once, until browned with no raw pink inside. Do not overcook — thin slices go from perfect to tough fast.
5. Check doneness. Thin slices at a hard sear reach 145°F (63°C) quickly (FoodSafety.gov safe minimum for beef) — spot-check with a thermometer.
6. Assemble immediately. Pour the hot beef and all its pan juices straight over the watercress. Drizzle with the dressing, scatter the peanuts and fried shallots if using, and serve right away.

Tips and ingredient notes

• Watercress sourcing: cultivated only. Wild or foraged watercress can carry liver flukes and other contaminants from the water it grows in — do not forage.
• Beef cut: sirloin or flank, sliced thin against the grain. Against the grain is non-negotiable for tenderness.
• Hot-on-cold timing: the beef must go from pan to platter in under a minute, and the salad should be served immediately.
• Marinade: oyster sauce and fish sauce together give the beef a savory glaze; the lineup stays simple on purpose.

Storage and food safety

Allergen note: contains fish (fish sauce), soy (oyster sauce), and peanuts (optional garnish — a major allergen). Beef must reach 145°F (63°C) internal temperature (FoodSafety.gov). This salad is meant to be assembled and eaten immediately; refrigerate any leftovers promptly and eat the same day.

Sources and references

• FoodSafety.gov — safe minimum internal temperature for beef (145°F).

Vietnamese Watercress Salad with Beef (Xa Lach Xoong Bo)

Xa lach xoong bo — hot seared beef over crisp watercress with a lime-fish sauce dressing.

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Servings: 4

Course: Salad

Cuisine: Vietnamese

Ingredients Method

Ingredients

  

• 1 lb (450 g) top sirloin or flank steak, sliced thin against the grain (about 1/4 inch)
• 2 bundles watercress (about 8 oz / 225 g), thick stems trimmed, washed very well and dried
• 1/2 small red onion, thinly sliced (soaking 10 minutes in cold water then draining takes the raw edge off — optional)
• 2 roma tomatoes, cut into wedges
• 1 tbsp neutral oil, plus more for searing
• 1/4 cup crushed roasted peanuts (optional garnish)
• 2 tbsp fried shallots (optional garnish)

Beef marinade

• 1 tbsp oyster sauce
• 1 tbsp fish sauce
• 1 tsp sugar
• 1 tsp minced garlic
• 1/2 tsp freshly ground black pepper
• 1 tbsp neutral oil

Dressing (lime-fish sauce vinaigrette)

• 3 tbsp fish sauce
• 2 tbsp fresh lime juice
• 2 tbsp sugar
• 3 tbsp water
• 1 small clove garlic, minced
• 1 Thai chile, sliced (optional)

Method

 

1. Prep the greens. Trim the watercress, wash thoroughly in several changes of water, and dry well — a salad spinner earns its keep here. Wet greens dilute the dressing. Use cultivated, food-grade watercress from a grocery store or market , not foraged. Arrange the watercress, red onion, and tomatoes on a serving platter.
2. Marinate the beef. Slice the steak thin against the grain (about 1/4 inch). Toss with all marinade ingredients and let sit 20 minutes at room temperature while you prep everything else.
3. Whisk the dressing. Combine the fish sauce, lime juice, sugar, and water, stirring until the sugar dissolves. Add the garlic and chile. Taste — it should be bright and balanced, not harsh.
4. Sear the beef. Heat a large skillet or wok over high heat with a thin film of oil until it just starts to smoke. Lay the beef in a single layer and cook about 2 minutes total, tossing once, until browned with no raw pink inside. Do not overcook — thin slices go from perfect to tough fast.
5. Check doneness. Thin slices at a hard sear reach 145°F (63°C) quickly (FoodSafety.gov safe minimum for beef) — spot-check with a thermometer.
6. Assemble immediately. Pour the hot beef and all its pan juices straight over the watercress. Drizzle with the dressing, scatter the peanuts and fried shallots if using, and serve right away.