In a large bowl, mix together the ground chicken, panko breadcrumbs, Parmesan cheese, parsley, and whisked egg until completely combined. Cut the mozzarella into ½-inch-sized cubes. Take about three or four tablespoons of the chicken mixture and wrap it around individual pieces of cheese. Roll into balls so that the cheese is in the center of the meatball.
Heat the oil in an oven-safe skillet over high heat. Sear the chicken meatballs on all sides until golden brown. Remove from the skillet and set aside. Without cleaning the skillet, pour in the diced tomatoes, tomato sauce, tomato paste, basil, and oregano. Stir everything together and bring to a bubble. Season with salt and pepper, then return the meatballs to the sauce.
Spread half of the shredded mozzarella over the top of the meatballs and sauce. Bake for fifteen minutes at 400°F. While the meatballs bake, cook the fettuccine according to the instructions on the package.
Sprinkle the remaining shredded mozzarella over the meatballs and broil for five minutes, until golden brown and bubbling. Garnish with additional parsley and Parmesan cheese, as desired. Serve on a bed of your favorite noodles or enjoy as an appetizer with toothpicks.