Mojo Marinated & Grilled Flank Steak

TO MAKE THE MOJO: Mash the raw garlic, chiles, salt, and cumin together in a mortar and pestle until fairly smooth. (Alternatively, use a food processor, pulsing until the ingredients are finely chopped but not puréed.) Scrape the mixture into a bowl and set aside.

Heat the olive oil until fairly hot but not smoking, and pour it over the garlic-chile mixture (the oil should sizzle when it hits the cool ingredients), stir, and let stand 10 minutes. This will cook the garlic slightly. Whisk in the sour orange juice and vinegar. Season with salt and pepper and set aside to cool completely.

FOR THE STEAK: Put the steak in a zip-top bag or a shallow bowl and pour in 1 cup of the cooled mojo. Seal and refrigerate for at least 2 hours or overnight, turning occasionally. Refrigerate the remaining 1 cup of mojo.

TO COOK AND SERVE: Light a charcoal or gas grill. When the grill is very hot, remove the steak from the marinade (discard the marinade), pat dry, and season with salt and pepper; cook 5 to 7 minutes on one side and 3 to 4 minutes on the other for medium rare. Remove from the grill and let rest for 5 minutes. (If you like, grill the Bermuda onions as well - you can put them on at the same time as the flank steak; grill 6 to 7 minutes per side.)

Meanwhile, warm the reserved mojo over low heat. Slice the flank steak very thinly on the bias and serve with the reserved mojo and the grilled onions.