1 tablespoon Thai chile powder (or red chile flakes)
1/4 cup vegetable oil
1 whole flank steak, about 2 pounds
Steps
Combine water and sugar in a small saucepan over medium heat, stirring until dissolved. Transfer to a small bowl; add fish sauce, lime juice, garlic, and chile powder and stir to combine. Reserve half of this mixture for later use.
Whisk oil into the remaining half. Add flank steak to a gallon-sized zipper-lock bag with this marinade, press out air, seal, and marinate—turning occasionally—for at least 1 hour and up to 12 hours.