Step 1

Wrap the flank steak in plastic wrap, and place in the freezer for 30 minutes.

Step 2

Unwrap and slice across the grain into 1/4-inch thick slices.

Step 3

In a medium bowl, combine all the "Marinade" ingredients. Add them to gallon size Ziploc bag, and add the steak slices.

Step 4

Marinate for at least 2-3 hours or overnight, turning the bag occasionally.

Step 5

Place a large cast-iron grill pan over medium-high heat and once heated through add 1 tablespoon of vegetable oil.

Step 6

Once the oil is hot, working in batches, add the steak slices to the pan in a single layer and cook until charred, flipping once, it takes about 2-3 minutes per side to cook.

Step 7

Add the remaining 1 tablespoon of vegetable oil and cook the rest of the steak.

Step 8

Serve immediately over rice if desired, garnished with chopped green onions and toasted sesame seeds.