In a bowl, whisk together the sweet chili sauce, soy sauce, garlic, and ginger. Add the chicken pieces and marinate in the refrigerator for at least 30 minutes (up to 2 hours).

In a separate bowl, place the cornstarch and season it with salt and pepper. Dredge the marinated chicken pieces in the cornstarch, shaking off any excess.

Heat the vegetable oil in a large skillet or wok over medium-high heat. Fry the coated chicken in a single layer until golden brown and cooked through, about 4-5 minutes per side. Work in batches if needed, then drain on paper towels.

In the same pan, add the remaining marinade and simmer until it thickens into a glaze. Return the fried chicken to the pan and toss to coat with the glaze for about 2-3 minutes.

Garnish with sliced green onions and sesame seeds. Serve over rice or noodles.