Preheat oven to 400 degrees F. Lightly oil a 9×13 baking dish or coat with nonstick spray.
In a large bowl, combine ground turkey, quinoa, garlic, onions, egg, soy sauce, sesame oil, Sriracha, salt and pepper, to taste. Using a wooden spoon or clean hands, stir until well combined. Roll the mixture into 1 1/4-to-1 1/2-inch meatballs, forming about 18-20 meatballs.
Place meatballs onto the prepared baking dish and bake for 18-20 minutes, or until all sides are browned and meatballs are cooked through.
To make the sauce, whisk together soy sauce, rice vinegar, ginger, sugar, sesame oil, Sriracha and 1/2 cup water in a small saucepan over medium high heat.
In a small bowl, whisk together cornstarch and 1 tablespoon water. Stir into soy sauce mixture until thickened, about 2 minutes.
Serve meatballs immediately with sauce, garnished with green onion and sesame seeds.
