In a large bowl, combine soy sauce, brown sugar, garlic, green onion, sesame seeds, sesame oil, and ground black pepper. Mix together until brown sugar dissolves.
Add skirt steak. Toss to thoroughly coat meat.
Refrigerate overnight or for at least 1 hour. Turn pieces every once in a while.
Oil grill pan with vegetable oil.
Grill steak over medium-high heat about 4 minutes per side, depending on thickness of meat.
Remove from grill, let steak rest, loosely covered in foil for 10 minutes.
Slice steak into thin pieces, cutting against the grain on an angle.
Serve over rice or in lettuce cups.
Recipe by Every Kitchen Tells A Story at https://everykitchentellsastory.com/asian-marinated-steak/