These skirt teaks need only a quick soak in the sesame-ginger marinade. Serve the grilled steak with a flavorful sauce made from the leftover marinade.
1. Whisk soy, oil, vinegar and sugar in small bowl to dissolve sugar. Add scallions, ginger, pepper flakes. Combine with steak in plastic food-storage bag. Refrigerate 25 minutes.
2. Prepare outdoor grill with medium-hot coals, or heat gas grill to medium-hot .
3. Remove steaks from marinade; transfer remaining marinade to pan.
4. Grill steaks 6 inches from heat 4 minutes per side (145 degrees F for medium-rare). Let rest 5 minutes.
5. Stir cornstarch into marinade in pan. Bring to boiling; simmer, stirring occasionally, 3 minutes.
6. Slice steak diagonally across grain. Serve with sauce.