To make a marinade: Stir soy sauce, honey, rice vinegar, sesame oil, brown sugar, sesame seeds, garlic, and ginger together in a bowl until well combined.
To make a sauce: Pour marinade mixture into a small saucepan and warm over medium-high heat. Whisk water and cornstarch together in a small bowl; add to marinade mixture. Bring to a boil, then reduce heat and simmer sauce, stirring frequently, until thickened, about 5 to 7 minutes.
