In a small bowl, whisk together the light soy sauce, oyster sauce, rice vinegar, brown sugar, minced garlic, grated ginger, cornstarch, water, and sesame oil until the cornstarch is completely dissolved.
Pour the mixture into a saucepan or directly into your stir fry pan. Bring the sauce to a gentle simmer over medium heat.
Cook for about 2 to 3 minutes, stirring constantly, until the sauce thickens to your desired consistency.
Remove from heat. Toss immediately with your cooked stir fry vegetables, noodles, meat, or seafood. Alternatively, let it cool and store in an airtight container in the refrigerator for 3 to 5 days.