In a large mixing bowl, combine ground chicken, breadcrumbs, grated Parmesan cheese, beaten egg, minced garlic, Italian seasoning, salt, and pepper. Use your hands or a spatula to mix until everything is well combined but don’t overmix.

Wet your hands slightly to prevent sticking, and form the mixture into meatballs, about 1 to 1.5 inches in diameter. Set these aside on a plate.

Pour the marinara sauce into the bottom of your slow cooker, allowing it to heat up and provide a flavorful base for the meatballs.

Place the meatballs carefully on top of the marinara sauce in the slow cooker. Ensure they’re well spaced so they can cook evenly.

Cover the slow cooker and set it to low heat. Cook for 4 to 6 hours, or high heat for 2 to 3 hours, until the meatballs are cooked through and tender.

Once they’re done cooking, serve them topped with fresh basil. Enjoy them over pasta, in a sub, or by themselves!