Preheat oven grill. Heat ghee in a heavy-based frying pan.
Add the schnitzels and fry on both sides until golden brown and cooked.
Remove from ghee and drain on kitchen paper.
Meanwhile, prepare the maize meal squares.
Bring the water and salt to the boil in a heavy-based saucepan.
Stir in the maize meal until mixture is smooth and allow to simmer covered for 30 minutes.
Mix the butter into the maize porridge.
Pour the porridge into a greased 25 x 35 cm baking tray.
Spread evenly with a spatula and allow to cool for 10 minutes.
Cut into squares. Place maize meal squares on a greased baking tray.
Place the schnitzels on top and follow with a layer of Napoletana sauce, ending with a layer of cheese.
Grill until the cheese has melted and the sauce is heated through.
Garnish with a sprig of thyme and serve.