Chili Powder–Rubbed Grilled Flank Steak

For Charcoal Grill: Ignite about 7 quarts charcoal and burn until coals are completely covered with thin coating of light-gray ash, 20 to 30 minutes. Pile coals on one-half of grill bottom, position grill rack and heat until very hot (you can hold your hand 5 inches above grill surface for 2 seconds).

For Gas Grill: Turn all burners on gas grill to high, close lid, and heat grill until hot, 10 to 15 minutes.

Rub steak all over wih spice mixture. Place directly over coals or on grate and grill until well-seared and dark brown on first side, 5 to 7 minutes (4 to 6 minutes covered for gas grill). Flip steak using tongs; continue grilling on second side until interior of meat is slightly less done than you want it to be when you eat it, 2 to 5 minutes more for medium-rare, (or 3 to 5 minutes, covered), on gas grill, depending on heat of fire and thickness of steak. Watch meat carefully to ensure that spice rub darkens but does not burn. Transfer meat to cutting board; cover loosely with foil, and let rest 5 to 10 minutes. Slice very thin, on bias against the grain; adjust seasoning with additional salt and pepper and serve immediately.