Preheat your oven to 400°F.
In a large bowl, combine the ground chicken, chopped onion, garlic powder, onion powder, Worcestershire sauce, salt, pepper, breadcrumbs, egg, and half of the Gruyère cheese. Mix until well combined.
Form the mixture into meatballs, about 1.5 inches in diameter, and place them on a baking sheet lined with parchment paper.
Drizzle the olive oil over the meatballs.
Bake in the preheated oven for 20-25 minutes or until they are cooked through and golden brown.
While the meatballs are baking, prepare the sauce by combining the beef broth, soy sauce, balsamic vinegar, and dried thyme in a small saucepan. Bring to a simmer over medium heat and let it cook for about 5 minutes.
Once the meatballs are done, remove them from the oven and place them in the saucepan with the sauce. Gently toss to coat the meatballs in the sauce.
Serve warm, topped with the remaining Gruyère cheese and parsley if desired.