Heat oven to 375°F.
Whisk together buttermilk and the egg in a large mixing bowl. Stir in panko and soak for 2 minutes to form a paste. Add ground chicken, chives, dill, garlic powder, onion powder, and salt. Mix until just combined.
Scoop 2 tablespoons of the mixture and flatten into a disc. Place a piece of brie in the center, then shape into a meatball, sealing the cheese inside. Repeat with remaining mixture and brie.
Warm a large skillet over medium heat. Add a thin layer of oil and sear meatballs on all sides until golden brown. Transfer to oven and bake for 10 minutes, or until cooked through. Remove from oven and serve with buttermilk dipping sauce.