- For the Marinade
- 1/2 cup palm sugar or brown sugar
- 1/4 cup water
- 3 tablespoons fish sauce
- 1/3 cup lime juice
- 2 cloves garlic, grated on a microplane zester
- 1 tablespoon Thai chili powder (or red chili flakes)
- 1/4 cup vegetable oil
- 1 whole flank steak, about 2 pounds
- For the Salad
- 1/2 cup loosely packed mint leaves
- 1/2 cup loosely packed cilantro leaves
- 1 small bunch chives, cut into 1 1/2-inch segments
- 1/2 cup loosely packed basil
- 4 shallots, thinly sliced
- 1 to 2 cups mung bean sprouts
Combine water and sugar in a small saucepan and heat over medium heat until completely dissolved. Transfer to a small bowl, add fish sauce, lime juice, garlic, and chili powder and stir to combine. Transfer half to a small container and reserve until step 3. Add oil to remaining half and whisk to combine. Place flank steak inside a gallon-sized zipper-lock bag with marinade. Press out air, seal bag, and allow meat to marinate, turning occasionally, for at least 1 hour and up to 12.
Remove steak from marinade and pat dry with paper towels. Ignite a large chimney full of coals and wait until they’re covered in grey ash. Spread evenly over 1/2 of grate, leaving the other half empty. Put the cooking grate in place, cover, and allow grill to preheat for 5 minutes. Scrape cooking grates clean, then place flank steak over hot side of grill. cook until well charred, about 3 minutes. Flip steak and continue to cook until second side is well charred, about 3 minutes longer. Transfer steak to cooler side of grill, cover, and cook until the center of the steak registers 125°F on an intant-read thermometer for medium-rare, or 135° for medium, about 5 minutes longer. Transfer to a cutting board, tent with foil, and allow steak to rest for at least 5 minutes.
Thinly slice beef against the grain and transfer to a large bowl. Add herbs, shallots, bean sprouts, and reserved marinade, and toss to combine. Serve immediately.