In a saucepan bring it to the boil 1.5 liters of water. As a boil add the chopped feta cheese. Add the peeled and grated potatoes and salt. Stir to melt the feta cheese and allow to boil for about half an hour. The butter is put in a pan and fry him carrots. Add the mixture to the soup, which is a nice orange color. Simmer for 5-10 minutes and serve warm.