Sweet and Sour Chicken Skewers

Name: Sweet and Sour Chicken Skewers
Ingredients: 1/2 cup apple cider vinegar; 1/4 cup brown sugar; 1/2 (20-ounce) can pineapple chunks, juice reserved; 1 tablespoon cornstarch, mixed with 1 tablespoon water; 1 red pepper, cut into 1-inch pieces; 1 lb boneless skinless chicken boneless thighs about four thighs; Kosher salt and freshly ground black pepper; 8 bamboo skewers, soaked in water for 30 minutes