Set your oven to preheat at 350°F (175°C).
In a large mixing bowl, combine the ground chicken with the eggs, breadcrumbs, grated Parmesan, minced garlic, oregano, and basil. Stir thoroughly until the mixture is well incorporated.
Place a sheet of heavy-duty foil or parchment paper on a clean work surface. Spread the chicken mixture over the foil, shaping it into a large rectangle using a silicone spatula or your hands.
Sprinkle half of the shredded mozzarella cheese over the center of the chicken mixture, followed by the chopped fresh parsley.
Using the foil as a guide, gently roll or fold the meat mixture into a log shape, securing the edges by folding the foil together snugly. Transfer the wrapped meatloaf onto a baking sheet.
Slice the onion, bell pepper, and mushrooms. Arrange the vegetables evenly across another section of foil-lined or greased baking sheet.
Place both the meatloaf and vegetables into the preheated oven. Bake for 35 to 40 minutes, adjusting for oven variance and baking pan depth.
Once baked, carefully open the foil around the meatloaf. It will be hot, so proceed with caution. Spoon the marinara sauce generously over the top and layer with the remaining mozzarella cheese.
Return the meatloaf to the oven, uncovered, for an additional 10 minutes or until the cheese is fully melted and bubbling.
Meanwhile, cook pasta according to the package instructions, if serving alongside.
Garnish the finished meatloaf with fresh parsley before serving.