The original recipe from The Essential New York Times Cookbook calls for marinating the meat for 6 to 36 hours. We don't have much experience with that full range of times. My husband puts it together one evening with plans to serve it the next.
Put a 2 pound flank steak in a large plastic bag to marinate overnight (ish) with:
1/4 Cup rice vinegar
1/4 Cup soy sauce
1 tablespoon minced fresh ginger
1 Tablespoon sesame oil
1 Tablespoon brown sugar
1/2 teaspoon crushed red pepper flakes.
When ready to cook, broil until it is done the way you like, several minutes per side works for us. Transfer to a cutting board. Let rest 10 minutes or so. Then slice thinly on the bias.