My absolute favorite way to marinate flank steak is with a sweet and spicy Thai-style sauce. I make mine with palm sugar (brown sugar will do fine), dried Thai chili flakes, fish sauce, garlic, and lime juice, which I then split in half, reserving half to toss with the meat after cooking, and adding some oil to the other half to use as a marinade. Once the meat is cooked, rested and sliced, I toss it all together with some reserved marinade, and a big herb salad with shallots and bean sprouts. It gets an awesome caramelized, charred crust on the grill from all the sugar, and the great thing is that it's delicious even when cold, making it the perfect dish for potlucks or relaxed backyard parties.
Note: An equivalent weight of skirt, flap, or hanger steak can be used in place of flank steak.
- 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 (see note)
- 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 instant-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. Proceed to step 4.
Alternatively, to finish indoors: Heat 2 tablespoons vegetable or canola oil in a large stainless steel or cast iron skillet over high heat until shimmering. Add steak and cook, turning frequently, until an instant-read thermometer registers 125°F for medium-rare or 135&Deg;F for medium, reducing heat as necessary if steak smokes excessively or starts to burn. Transfer to a wire rack set in a rimmed baking sheet and allow to rest 5 to 10 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.