Step 1: Prepare the Chicken

1. In one bowl, whisk together cornstarch, flour, salt, and pepper.
2. In a separate bowl, beat the eggs.
3. Dredge the chicken pieces in the flour mixture, then dip into the eggs, and coat again in the flour mixture for an extra crispy texture.

Step 2: Fry the Chicken

1. Heat about 1 inch of vegetable oil in a deep skillet over medium-high heat.
2. Fry the chicken in batches for about 3-4 minutes per side until golden brown and cooked through.
3. Transfer to a paper towel-lined plate to drain excess oil.

Step 3: Prepare the Sauce

1. In a large pan over medium heat, add a little oil and sauté garlic, ginger, and red pepper flakes for about 30 seconds.
2. Add the bell pepper and pineapple chunks, cooking for another 2 minutes until slightly softened.
3. Stir in the sweet chili sauce, soy sauce, and rice vinegar, bringing to a gentle simmer.

Step 4: Combine and Serve

1. Add the crispy chicken to the sauce, tossing to coat evenly.
2. Garnish with sliced green onions and sesame seeds.
3. Serve hot over steamed rice or alongside stir-fried vegetables.