In a large mixing bowl, combine the ground turkey, bread crumbs, beaten egg, sage, thyme, onion powder, garlic powder, salt, and black pepper. Mix until well combined.

If using, add the chopped celery, onion, and parsley to the mixture and stir until evenly distributed.

Preheat the oven to 375°F (190°C).

Using your hands, form the turkey mixture into balls about 1.5 inches in diameter and place them on a baking sheet lined with parchment paper.

Bake in the preheated oven for 25 minutes or until the internal temperature reaches 165°F (74°C) and the balls are golden brown.

Remove from the oven and let cool slightly before serving.