For the marinade:

• 1/3 cup ketchup
• 1/3 cup brown sugar
• 1/3 cup soy sauce
• ¼ cup canned pineapple juice
• 2 tbsp olive oil, divided, plus more for brushing grill
• 5 tsp rice vinegar
• 4 garlic cloves, minced 
• 1 tbsp minced ginger
• ½ tsp sesame oil
• salt and black pepper to taste

For the kebabs:

• 1 ½ pounds boneless, skinless chicken breast, chopped into 1 cubes
• 3 cups fresh pineapple chunks
• 2 large green peppers, chopped into 1 inch pieces
• 1 large red onion, chopped into 1 inch pieces
• 2 tbsp olive oil