Ingredients: 

1/4 cup lemon-lime carbonated beverage
1/4 cup dry sherry
1/4 cup soy sauce
3 tablespoons granulated sugar
3 tablespoons white vinegar
1/2 teaspoons garlic powder
1/4 teaspoon salt
1/4 teaspoon freshly ground pepper
2 pounds sirloin steak, cut into 1-inch cubes
2 medium onions, cut into wedges
1/2 pound fresh whole mushrooms
2 medium green, red or yellow bell peppers (or combination)
1 small pineapple, cut into 1-inch chunks
Wooden skewers, soaked in water for 30 minutes