Sweet and Tangy Hawaiian Chicken with Pineapple and Peppers

Ingredients

• 1/3 cup ketchup
• 1/3 cup packed dark brown sugar
• 1/3 cup low-sodium soy sauce
• 1/4 cup canned pineapple juice
• 4 tablespoons olive oil, divided, plus more for brushing grill
• 1 1/2 tablespoons rice vinegar
• 4 garlic cloves, minced
• 1 tablespoon minced fresh ginger
• 1/2 teaspoon sesame oil
• Salt, to taste
• Freshly ground black pepper, to taste
• 1 3/4 pounds boneless, skinless chicken breast, cut into 1 1/4-inch cubes
• 3 cups fresh pineapple, cubed (about 3/4 of a 3-pound pineapple)
• 1 1/2 large green bell peppers, chopped into 1 1/4-inch pieces
• 1 large red onion, chopped into 1 1/4-inch pieces