Step 1: Preheat the Oven
Preheat your oven to 350°F (175°C). Lightly grease a 9x13-inch baking dish.
Step 2: Prepare the Chicken
Coat the chicken pieces in cornstarch, shaking off any excess.
Dip each piece into the beaten eggs, ensuring it’s fully coated.
Heat the vegetable oil in a large skillet over medium-high heat.
Pan-fry the chicken pieces in batches until golden brown on the outside (they don't need to be fully cooked). Transfer the chicken to the prepared baking dish.
Step 3: Make the Sauce
In a medium saucepan, combine the brown sugar, soy sauce, pineapple juice, rice vinegar, garlic, ginger, ketchup, and red pepper flakes (if using).
Bring the mixture to a simmer over medium heat, stirring occasionally.
Add the cornstarch slurry and whisk until the sauce thickens, about 1-2 minutes.
Step 4: Combine and Bake
Pour the sauce evenly over the chicken in the baking dish.
Add pineapple chunks on top for extra flavor.
Bake uncovered for 30-35 minutes, stirring halfway through to ensure the chicken is evenly coated.
Step 5: Garnish and Serve
Remove from the oven and let it rest for 5 minutes. Garnish with sliced green onions and sesame seeds before serving. Pair with steamed white rice, fried rice, or sautéed vegetables.