01 - Preheat oven to 400°F. Line a baking tray with parchment paper or lightly grease with oil.
02 - Heat 1 tablespoon of olive oil in a skillet over medium heat. Sauté diced onion for 3 to 4 minutes until tender. Add minced garlic and sauté for 1 minute more. Remove from heat and allow to cool slightly.
03 - In a large mixing bowl, blend ground chicken, sautéed onion and garlic, fresh or dried sage, dried thyme, salt, black pepper, and optional nutmeg until evenly incorporated.
04 - Add breadcrumbs and the lightly beaten egg to the chicken mixture. Mix gently until just combined, avoiding overworking the mixture.
05 - With damp hands, portion approximately 1 heaping tablespoon of mixture per ball. Shape into balls and arrange evenly on the prepared baking tray.
06 - Drizzle or brush the remaining 1 tablespoon olive oil evenly over the chicken balls.
07 - Bake in the center of the oven for 20 to 25 minutes, turning the balls halfway through, until golden and internally cooked through (internal temperature should reach 165°F).
08 - Serve hot as an appetizer or main dish, optionally pairing with dipping sauces or side dishes.