Slice flank steak into thin strips.

Combine ginger, garlic, onion, soy sauce, sugar, sherry wine, and ajinomoto in a bowl.

Whisk the ingredients together to create the teriyaki marinade.

Place the sliced beef into the marinade.

Marinate the beef in the refrigerator for at least 1 hour, or longer for enhanced flavor.

Thread the marinated beef onto skewers.

Preheat the barbeque grill to medium-high heat.

Place the skewers on the grill.

Grill the shish kabobs, turning occasionally, until the beef is cooked to your desired temperature.

Remove the shish kabobs from the grill and let them rest for a few minutes before serving.