Whisk cornstarch and water in a small bowl until fully smooth. Set aside.
In a medium bowl, combine sweet chili sauce, soy sauce, minced garlic, rice vinegar, sesame oil, and red pepper flakes if using. Whisk until fully combined.
Stir cornstarch slurry into the sauce base and mix until evenly distributed.
Heat wok or skillet over high heat. Cook protein, push to sides, pour sauce into center. Stir constantly 30–45 seconds until glossy and thickened. Toss everything together and serve immediately.
Notes
Mae Ploy sweet chili sauce delivers the best flavor and body for this recipe. Skip cornstarch entirely to use this as a cold dipping sauce. Store refrigerated up to 6 days. Freeze in ice cube portions up to 2 months.
Keyword sweet chili stir fry sauce, homemade sweet chili sauce, easy Asian glaze