Step 1

In a medium mixing bowl whisk together soy sauce, brown sugar, rice vinegar and sesame oil until sugar is dissolved.

Step 2

Slice flat iron steak at a 45° angle, about 1/4-inch thick to yield slices about 1 1/2-inches wide. Stir into marinade and refrigerate at least 1 hour.

Step 3

Preheat grill to medium high. Thread steak slices onto skewers and grill about three minutes per side.

Step 4

Garnish with a generous shake of sesame seeds and sprinkling of green onion.