In a large bowl, combine the ground beef (or turkey), breadcrumbs, egg, green onions, soy sauce, garlic powder, ginger powder, salt, and pepper. Mix until well combined.
Form the mixture into small meatballs, about 1 inch in diameter, and set them aside on a baking tray.
In a separate bowl, whisk together the sweet chili sauce, rice vinegar, and sesame oil.
Place the meatballs into the crockpot and pour the sweet chili sauce mixture over them, ensuring all meatballs are well coated.
Cover the crockpot and cook on low for 6-8 hours or on high for 3-4 hours, until the meatballs are cooked through and tender.
Once cooked, gently stir the meatballs in the sauce to coat them again before serving.
Serve hot, garnished with sesame seeds and extra chopped green onions if desired.
Notes
Serve with steamed rice or noodles for a complete meal.