In a large mixing bowl, combine chicken, Dijon mustard, garlic powder, parsley, and sea salt. Mix until combined.
Form the mixture into 10 golf ball-sized meatballs, reserving about half a cup of the meat. Create a divot in the center of each meatball, and fill with ½ teaspoon of mashed avocado. Cover the divot with 1 tablespoon from the reserved ground chicken to seal.
Heat the ghee over medium heat in a skillet. Add 4–5 meatballs, and cook for 12 minutes, turning the meatballs to evenly brown on all sides. Set aside, and keep warm.