Pour the chicken stock into a pot together with the butter and the salt. Now bring this to a boil on a medium heat. Once it is boiling add the polenta and while stirring bring this to a boil once more. Then clean the sides of the pot. Put a lid on the pot and cook it in an oven of 160 degrees Celsius for 45 minutes. Now take the pot out of the oven and add the parmesan cheese to the polenta. Mix this and be aware that the pot is very hot! Then pour it onto a tray that’s laid with a silicon sheet. Put another sheet on top and make it level with a rolling pin. Now let it cool down in your fridge. After that remove the silicon sheet and cut the polenta into the desired shape. Fry it in a frying pan till golden on both sides.