Line an oven dish with baking parchment or clingfilm .
In a saucepan, bring the water to the boil and add the salt and polenta while whisking.
Switch to a medium heat and simmer for around 10 minutes while stirring until the polenta thickens and pulls away from the side of the pot.
Take off the heat and stir in the butter and parmesan until they’re thoroughly combined.
Pour the mixture into the prepared baking dish and mould into a rectangular shape. If you’re in a rush pop the dish into the fridge for 30 minutes and then move to the freezer for another 30 minutes so the polenta will set. Ideally this should be made the night before and left in the fridge.
Remove the set polenta from the baking dish and turn it onto a chopping board. Cut it into inch-wide cubes.
Heat some oil in the frying pan and fry the cubes for about 20 minutes over a medium-high heat until crispy.
Sprinkle with salt and pepper while frying.