Ingredients (4 Servings)
2 tablespoons light brown sugar
1 tablespoon ancho chile powder
1 tablespoon paprika
2 teaspoons kosher salt
2 teaspoons freshly ground black pepper
1 teaspoon cayenne pepper
1 teaspoon granulated garlic
1 teaspoon English mustard powder
½ teaspoon ground coriander
½ teaspoon ground cumin
STEAK AND SALSA
2 tablespoons olive oil, plus more for grill
3 ears of corn, shucked
¼ red onion, finely chopped
1 jalapeño, seeds removed, finely chopped
1 pint cherry tomatoes, halved
1 cup fresh cilantro, coarsely chopped
⅓ cup fresh lime juice
Kosher salt, freshly ground pepper
1½ pounds flank steak
Combine brown sugar, chile powder, paprika, salt, pepper, cayenne, granulated garlic, mustard powder, coriander, and cumin in a small bowl.
STEAK AND SALSA
Prepare a grill for medium-high heat; oil grate. Grill corn, turning occasionally, until lightly browned all over, 8–10 minutes; let cool. Cut kernels from cobs and place in a medium bowl. Add onion, jalapeño, tomatoes, cilantro, and lime juice to corn and toss to combine; season with salt and pepper. Set salsa aside.
Meanwhile, coat steak with all of dry rub, packing on more than once if needed, and drizzle with 2 Tbsp. oil to help rub adhere. Grill steak, turning occasionally and moving to a cooler spot on grill as needed to control flare-ups, until nicely browned and an instant-read thermometer inserted into the thickest part registers 130°, about 4 minutes per side for medium-rare. Transfer to a cutting board and let rest 10 minutes.
Return steak to grill just to recrisp exterior, about 1 minute per side. Transfer back to cutting board and slice against the grain. Serve topped with salsa.
Do Ahead: Salsa can be made 1 day ahead. Cover and chill.