Mozzarella-Stuffed Pesto Turkey Meatballs

3 pounds ground turkey

1 cup finely chopped onion

4 garlic cloves, minced

1 egg

1 cup Italian-style bread crumbs

½ cup grated Parmigiano-Reggiano cheese

½ cup chopped fresh flat-leaf parsley

¼ cup prepared pesto

¼ cup milk

1 tablespoon salt

2 teaspoons fresh ground black pepper

1 pound fresh mozzarella, cut into small cubes

3 tablespoons extra-virgin olive oil

2 (24 ounce) jars marinara sauce

Preheat an oven to 375 degrees F (190 degrees C).

Place the ground turkey, onion, garlic, egg, bread crumbs, Parmigiano-Reggiano cheese, parsley, pesto, milk, salt, and black pepper in a bowl. Mix until evenly blended, then form into 1 3/4-inch meatballs. Make a hole in the meatball with your finger and place a cheese cube in the hole. Seal the meatball around the cheese and place on a nonstick baking sheet. Drizzle the olive oil over the meatballs.

Bake in the preheated oven until the meatballs are no longer pink in the center, about 30 minutes. Heat the marinara sauce in a saucepan over low heat. Bring to a simmer, and place the baked meatballs in the marinara sauce for about 2 minutes.