A simple marinade transforms this steak into a must try steak recipe!
In a bowl whisk together the soy sauce, Gochujang chili sauce, ginger paste, garlic paste, brown sugar, and sesame oil.
Put the flank steak in a dish or gallon size plastic bag. Pour 3/4 of the marinade over the steak and mix until evenly coated. Save the remaining marinade to brush over top during grilling. Marinate the steak at least 1 hour or overnight.
Place the steak on a grill over medium high heat for 3-4 minutes per side for medium doneness. Brush with the remaining marinade during grilling.
Let the steak rest for a few minutes. Slice the flank steak against the grain and garnish with sesame seeds and green onions if desired. Serve with the optional dipping sauce if desired.