In a large mixing bowl, add ground beef or chicken, breadcrumbs, egg, minced garlic, grated ginger, salt, and black pepper. Mix everything gently until just combined—avoid overmixing to keep the meatballs soft and tender.
Take small portions of the mixture and roll them into evenly sized meatballs using your hands. Set them aside on a plate.
Heat oil in a large non-stick pan over medium heat. Add the meatballs in batches and cook them, turning occasionally, until they are nicely browned on all sides and fully cooked through. Remove from the pan and set aside.
In the same pan, add soy sauce, honey (or sugar), and water. Stir well and let it simmer for a few minutes so the flavors combine.
In a small bowl, mix cornstarch with a little water to make a slurry. Pour it into the sauce while stirring continuously. Cook until the sauce thickens and becomes glossy and sticky.
Add the cooked meatballs back into the pan and toss them gently until they are fully coated in the teriyaki sauce. Let them cook together for 2–3 minutes.
Meanwhile, cook the rice according to package instructions until soft and fluffy.
Serve the sticky teriyaki meatballs over warm rice, garnish if desired, and enjoy your delicious homemade meal.