1-First, preheat your oven to 400 degrees Fahrenheit and line a large baking sheet with parchment paper or foil, spraying the foil with cooking spray if you choose that option.

2-Next, dice the chicken, onion, and bell peppers into pieces of similar size, then drain the pineapple chunks while keeping the juice aside.

3-In a small bowl, mix the 2 tablespoons of pineapple juice, 1/3 cup soy sauce, 1 tablespoon cornstarch, 4 tablespoons brown sugar, 1 teaspoon garlic salt, and 1 teaspoon red pepper flakes until everything is smooth and well combined.

4-Place the diced chicken, onion, and peppers into a large bowl, pour the sauce over them, and stir until they’re evenly coated.

5-Spread the mixture on the prepared sheet pan in a single layer to avoid overcrowding, which helps with even cooking.

6-Bake for 10 minutes, then remove the pan and toss the ingredients gently before adding the 20 ounces of pineapple chunks.

7-Return it to the oven for another 10 to 15 minutes, or until the chicken is fully cooked through.