Place your frozen meatballs in the crockpot, spreading them out evenly.
In a medium bowl, combine water, soy sauce, honey, brown sugar, sesame oil, rice vinegar, garlic powder, and ground ginger. Whisk until well mixed, then taste and adjust seasonings if needed.
Add cornstarch to the sauce mixture and whisk until completely dissolved with no lumps remaining.
Pour this sauce over the meatballs in the crockpot, gently stirring to ensure all meatballs are coated.
Cover and cook on LOW for 3-5 hours, stirring halfway through the cooking time to ensure even coating and heating.
The sauce will gradually thicken as it cooks. When done, the meatballs should be heated through and the sauce should have a glossy, sticky consistency.
Garnish with sesame seeds and chopped green onions before serving with white rice for a filling meal.
Notes
Sauce thickness - If after 4-5 hours your sauce isn't thick enough, remove the lid and cook on HIGH for an additional 15-20 minutes, stirring occasionally.
Meatball selection - For best results, use unflavored frozen meatballs like homestyle, Angus beef, or plain turkey/chicken varieties.
Sauce adjustment - Always taste your sauce before adding cornstarch. You can add more honey or brown sugar for sweetness, soy sauce for saltiness, or rice vinegar for tanginess.
Even cooking - Stir the meatballs gently about halfway through cooking to ensure they're all evenly coated with the sauce as it thickens.
Garnish last - Add the sesame seeds and green onions just before serving to maintain their texture and vibrant color.