Sweet and Sour Chicken – Crispy, Tangy, and Better Than Takeout

Ingredients

• 1 cup pineapple juice ()
• ½ cup distilled white vinegar
• ½ cup sugar
• 3 tablespoons ketchup
• 2 tablespoons soy sauce
• ¼ teaspoon crushed red pepper flakes
• 1½ tablespoons cornstarch
• ½ cup all-purpose flour ()
• ½ cup cornstarch
• 1 teaspoon baking powder
• ¼ teaspoon baking soda
• Heaping teaspoon salt
• ¼ teaspoon freshly ground black pepper
• ⅔ cup water
• 1½ tablespoons vegetable oil, plus more for cooking
• 1 pound chicken tenderloins or boneless, skinless chicken breasts, trimmed and cut crosswise on slight bias into 1-inch (2.5-cm) chunks
• 1 tablespoon vegetable oil ()
• 2 red bell peppers, cut into 1-inch 1-inch (2.5-cm) pieces
• 1 small red onion, cut into 1-inch 1-inch (2.5-cm) chunks