In a large mixing bowl, combine ground chicken, ¼ cup dill, onion, carrot, rice, garlic, salt, pepper and lemon zest. Gently mix with your hands until well combined.

Gently form the mixture into 24 meatballs, each about 1 ¼ inches in diameter, placing them on a plate or baking pan. Cover and chill for at least 20 minutes or up to 24 hours.

In a large pot, bring stock to a boil over high heat. Reduce to medium and use a slotted spoon to carefully add meatballs to the pot. Simmer for 20-25 minutes, or until meatballs are cooked through.

In a separate bowl, whisk together eggs and lemon juice. Slowly drizzle a ladleful of hot broth into the egg mixture, whisking constantly to temper the eggs. Repeat with another ladleful of broth. Gradually whisk the tempered egg mixture into the pot with the meatballs.

Heat gently, stirring constantly, until the soup thickens slightly. Do not boil.

Stir in remaining dill. Serve immediately, garnished with freshly grated nutmeg (optional).