Step 1: Prepare the chicken by patting the pieces thoroughly dry with paper towels. Season generously with salt and black pepper. If desired, you can lightly dust the chicken pieces with 1 tablespoon of cornstarch for an extra crispy coating.
Step 2: Heat the olive oil in a large skillet or wok over medium-high heat. Once hot, add the chicken pieces in a single layer, ensuring not to overcrowd the pan. Cook for 3-4 minutes per side, or until golden brown and cooked through. You may need to cook the chicken in two batches to achieve proper browning. Remove the cooked chicken from the pan and set aside.
Step 3: Reduce the heat to medium. Add the minced garlic and grated ginger to the same pan (add a tiny bit more oil if necessary). Sauté for 30-60 seconds until fragrant, being careful not to burn them.
Step 4: Pour in the sweet chili sauce, low-sodium soy sauce, and rice vinegar. Bring the mixture to a gentle simmer, stirring continuously. If you prefer a thicker sauce, stir in the cornstarch slurry (1 teaspoon cornstarch mixed with 1 tablespoon cold water) and let it cook for another minute until the sauce reaches your desired consistency.
Step 5: Return the cooked chicken pieces to the pan, tossing them gently to coat evenly with the luscious sweet chili sauce. Cook for an additional 1-2 minutes, allowing the chicken to fully absorb the flavors and the sauce to adhere.
Step 6: Garnish generously with chopped green onions and sesame seeds before serving.