1/2 cup low sodium soy sauce
1/4 cup olive oil
3 garlic cloves minced
1/4 cup freshly squeezed lime juice
2 tablespoons brown sugar
1 teaspoon cumin
1 teaspoon freshly ground black pepper
1/4 teaspoon cayenne
2 lbs. skirt steak
Combine all of the marinade ingredients in a bowl and whisk together. Place skirt steak in a large container with lid or ziploc bag. Pour marinade over. Cover container or seal bag and refrigerate. Marinate for at least 3 hours or overnight. Remove from refrigerator 30 minutes before grilling to bring to room temperature.
Prepare grill for high heat (or preheat oven broiler). Remove meat from marinade; discard marinade. Grill over direct high heat, turning once, 3-4 minutes each side for medium-rare. (If using the oven, arrange meat on in one layer on a broiler pan. Broil, turning once, 4 minutes per side). Transfer meat to cutting board. Tent with foil and let rest 10 minutes. To serve, slice skirt steak against the grain on the diagonal in 3″ strips.