2 pounds boneless sirloin steak
1/2 cup soy sauce
1/4 cup vinegar
2 tablespoons brown sugar
2 tablespoons minced onions
1 tablespoon vegetable oil
1 garlic clove, minced
1/2 teaspoon ground ginger
1/8 teaspoon pepper

Trim fat from steak and slice lengthwise into 1/2-in strips; place in a large glass bowl.

Combine all remaining ingredients; pour over meat and toss gently. Cover and refrigerate for 2 to 3 hours.

Drain, discarding marinade. Loosely thread meat strips onto skewers. Grill over medium-hot coals, turning often, for 7 to 10 minutes or until meat reaches desired doneness. (If using the George Foreman grill, check for doneness after 3 or 4 minutes.) Remove from skewers and serve.