The marinade for this grilled flank steak recipe borrows its flavors from Mexico--cilantro, lime, and fresh jalapeño chile.
Whirl in a blender or food processor until smooth: cilantro, lime rind, lime juice, oil, jalapeno, garlic, salt, cumin and pepper. Combine marinade and flank steak in plastic food-storage bag. Refrigerate overnight.
Prepare outdoor grill with medium-hot coals, or heat gas grill to medium-hot, or heat oven broiler and coat broiler-pan rack with nonstick cooking spray. Remove steak from marinade. Discard marinade.
Grill steak or broil 2 inches from heat until instant-read thermometer inserted in center registers 145 degrees F for medium-rare, about 4 minutes per side, or until desired doneness.
Remove flank steak to cutting board. Let rest for 10 minutes. Cut flank steak diagonally across grain into thin slices. Makes 6 servings.