Grilled Steak Kebabs

Bahan-bahan (8 porsi)

• 2 1/2 lbs beef tri tip or petite sirlion (cut into 1 1/2" thick pieces)
• 2 medium zucchini (cut into thick rings)
• 1 medium purple onion (cut into 1" pieces)
• 1/4 cup white vinegar
• 1/4 cup soy sauce
• 1/4 cup BBQ sauce (honey flavor, or sweet and smoky)
• 2 Tbsp Worcestershire sauce
• 2 tsp sesame oil
• 1 tsp garlic salt
• 1/2 tsp black pepper