Before You Begin
Prepare your cookware as needed. Cooking times and results may vary depending on your equipment and ingredients.
Preheat the oven to 400°F (200°C) and line a baking sheet with parchment paper to help prevent sticking.
In a large bowl, combine the ground chicken, Parmesan cheese, panko breadcrumbs, egg, milk, garlic, onion, Italian seasoning, salt, and pepper. Mix gently until just combined.
Shape the mixture into evenly sized meatballs (about 1½ inches wide) and place them spaced apart on the prepared baking sheet.
Bake for about 18–20 minutes, or until the meatballs appear lightly golden, firm, and opaque in the center with no pink.
Remove the baking sheet from the oven. Spoon marinara sauce over each meatball and sprinkle with mozzarella cheese.
Return to the oven and bake for 3–5 minutes, or until the cheese melts and begins to bubble.
Let the meatballs rest briefly, then serve warm with pasta, vegetables, or bread if desired.