- 1 2″ piece lemongrass, tough outer layers removed, lightly smashed, very thinly sliced
- 1/4 cup (packed) light brown sugar
- 3 tablespoons fish sauce
- 2 tablespoons Asian sweet chili sauce
- 1 1/2 pounds hanger steak, center membrane removed, cut into 4 pieces
- 1/2 cup unseasoned rice vinegar
- 2 tablespoons Asian sweet chili sauce
- 1 teaspoon finely grated lemon zest
- 1 medium cucumber, thinly sliced
- 1 medium carrot, peeled, julienned
- 1/2 small daikon, peeled, julienned
- 1/2 small red onion, thinly sliced
- Kosher salt, freshly ground pepper
- 1/2 cup chopped fresh cilantro
- 1/4 cup chopped unsalted, dry-roasted peanuts
- Combine lemongrass, brown sugar, fish sauce, and sweet chili sauce in a resealable plastic bag. Add steak; seal, turn to coat, and chill at least 3 hours.
- DO AHEAD: Steak can be marinated 12 hours ahead. Keep chilled.
- Whisk vinegar, sweet chili sauce, and lemon zest in a medium bowl. Add cucumber, carrot, daikon, and onion and toss; season with salt and pepper. Cover and chill at least 2 hours.
- Meanwhile, remove steak from marinade and let sit at room temperature 30 minutes.
- Prepare grill for medium-high heat. Season steak with salt and pepper and grill, turning occasionally, 8–10 minutes for medium-rare. Let rest 5 minutes before thinly slicing.
- Drain salad. Serve with steak, topped with cilantro and peanuts.
- DO AHEAD: Cucumber salad can be made 4 hours ahead. Keep chilled.