In a large mixing bowl, combine ground chicken, breadcrumbs, parmesan, egg, salt, and pepper. Add onion and garlic, mixing until well blended. Shape into meatballs.

Heat olive oil in a large skillet over medium-high heat. Carefully add meatballs, browning on all sides for about 6-8 minutes. Remove from skillet.

In the same skillet, add olive oil if needed. Sauté onion, carrot, and celery for about 5 minutes. Stir in tomato paste and cook for an additional minute.

Pour in the red wine, scraping any browned bits from the pan. Add chicken broth if desired. Bring to a simmer, cooking down for 15-20 minutes.

Return the meatballs to the skillet, ensuring they are immersed in the sauce. Cover and let simmer for 20-30 minutes on low heat.

In a separate pot, bring water or broth to a boil. Gradually whisk in polenta, reduce heat, and stir frequently for 10-15 minutes until creamy.

To serve, spoon polenta onto each plate, top with meatballs and sauce, and garnish with parsley.