Preheat the grill to medium high heat. Trim fat from beef steak. Cut beef into 3/4-inch cubes.

Place beef in glass or plastic bowl.

Mix tamari, sherry, ginger, garlic, and maple syrup in a small bowl and then pour over beef.

Cover and refrigerate, stirring occasionally, at least 1 hour.

Thread beef, tomatoes, onions, and peppers on 6 skewers, and place on grill.

Brush kabobs with left over marinade, turning often, and cook for approximately 7-8 minutes for medium cooked meat.