Pule cheese

Pule cheese or magareći sir, is a Serbian cheese made from 60% Balkan donkey milk and 40% goat's milk.
Pule is produced in Zasavica Nature Reserve, as conceived by Slobodan Simić, Zasavica Special Nature Reserve Manager and former Serbian MP.
Pule is reportedly the "world's most expensive cheese", fetching US$600 per kilogram. It is so expensive because of its rarity: there are only about 100 jennies in the landrace of Balkan donkeys that are milked for Pule-making and it takes 25 litres (6.6 gallons) of milk to create one kilogram (2.2 pounds) of cheese.