2 teaspoons granulated sugar
1 teaspoon instant espresso powder
2 tablespoons coarsely ground black pepper
1 teaspoon fine sea salt
2 teaspoons mild chili powder
1 flank steak, about 1 1/2 pounds
1 tablespoon vegetable oil
Preheat gas grill to medium-high heat. In a small bowl, combine sugar, espresso, black pepper, salt, and chili powder. Rub steak all over with vegetable oil. Press spice mixture onto both sides of steak.
Cook on first side until well seared, about 8 minutes. Flip and cook until second side is seared and center of steak registers 135?F on an instant-read thermometer, about 6 minutes longer. Transfer to cutting board, tent with foil, and allow meat to rest 10 minutes. Slice thinly against the grain, and serve.