Cut chicken breasts into uniform 1-inch cubes. In a mixing bowl, combine sweet chili sauce, soy sauce, minced garlic, and minced ginger. Add chicken pieces, toss to coat, cover and refrigerate for at least 30 minutes, or up to 2 hours for maximum flavor.

Place cornstarch in a shallow bowl and season lightly with salt and pepper. Remove marinated chicken from refrigerator, reserving all the marinade. Using a slotted spoon, transfer chicken to cornstarch bowl, allowing excess marinade to drip off. Coat each piece evenly.

Heat vegetable oil in a large skillet or wok over medium-high heat until shimmering (around 350°F). Add coated chicken in a single layer without overcrowding. Cook for 4-5 minutes per side until golden brown and internal temperature reaches 165°F. Work in batches if necessary.

Transfer cooked chicken to a paper towel-lined plate. In the same skillet, reduce heat to medium and add reserved marinade. Bring to a full rolling boil for at least 2 minutes, then simmer until thickened to a syrupy consistency, about 3-4 minutes total.

Return fried chicken to the skillet with simmering sauce. Toss gently using tongs to coat every piece thoroughly. Cook for 2-3 minutes more, allowing flavors to meld. Taste and adjust seasoning as needed.

Transfer glazed chicken to serving platter using tongs or slotted spoon. Sprinkle with sliced green onions and toasted sesame seeds. Serve immediately over jasmine rice or noodles.