Begin by setting the oven to a temperature of 400°F (200°C) to preheat.

Using a skillet of twelve-inch diameter that comes with a cover, carefully unpack and place the frozen French Onion Soup in the pan. Introduce the 500ml of water. Over a high flame, bring the water to a boiling point and subsequently incorporate the pasta.

Ensure the skillet is covered and monitor the pasta as it cooks. Adhere to the package's guidance regarding cooking time, and intermittently stir to avoid the pasta from adhering to the skillet's base.

Once the pasta has achieved the desired consistency, turn off the heat. Introduce the unsalted butter, ensuring it is thoroughly integrated by stirring. The cheese should be added in small quantities, preferably in 2 or 3 batches, and continue stirring until a majority of the cheese has melted. This process should take approximately 2 minutes. Conclude by seasoning with salt and black pepper according to personal preference.

Thoroughly grease an 8×8 baking dish with butter. Transfer the macaroni and cheese mixture into this dish, ensuring even distribution.

Garnish the mixture with an extra 113g of your chosen cheese. Bake the dish for 15 minutes or until the top layer achieves a browned appearance and exhibits a bubbly texture. It is recommended to serve this dish while still warm.