Start by heating 1 tablespoon of olive oil in a skillet over medium heat. Add 80g of finely diced onion and 2 minced garlic cloves. Sauté until soft and translucent, about 5 minutes. Remove from heat and let cool.

In a large mixing bowl, combine 900g of ground chicken, the cooled onion and garlic mixture, 60g of seasoned breadcrumbs, 2 teaspoons of milk, 30g of grated Parmesan cheese, 1 egg, 2 tablespoons of chopped fresh parsley, 1 teaspoon of Italian seasoning, and ½ teaspoon of salt. Gently mix until just combined.

Prepare a baking sheet with foil. Shape two-thirds of the meat mixture into a rectangle about 1 inch thick. Create a well in the center and layer 3 slices of mozzarella cheese strings. Fold remaining meat over cheese and seal the edges.

Spread 120ml of marinara sauce evenly over the meatloaf. Preheat oven to 200°C (400°F) and bake for 45 minutes.

Prepare topping by mixing 2 tablespoons of panko breadcrumbs, 20g of grated Parmesan cheese, 1 tablespoon of melted butter, and 1 tablespoon of chopped parsley. After 45 minutes, sprinkle topping over meatloaf and return to oven for 15-20 minutes until golden and crisp.

Once baked, let the meatloaf rest for 10 minutes. Slice and serve, revealing the melted cheese center.