In a remote Serbian mountain village, chefs are cooking up delicacies to make your mouth water or your stomach churn. At the seventh annual World Testicle Cooking Championship, visitors watch and sometimes taste as teams of chefs cook up bull, boar, camel, ostrich and even kangaroo testicles.

"This festival is all about fun, food and bravery," said Ljubomir Erovic, the Serbian chef who organises the event in Ozrem and has published a testicle cookery book. The food politely called "white kidneys" in Serbian is believed to be rich in testosterone. In the Balkans, it is considered to help men's libido.

Testicles cooking in a pot. Photograph: Marko Drobnjakovic/AP

"The bulls' testicles are the best, goulash-style," said last year's winner, Zoltan Levai, stirring a metal pot heated by a wood fire and filled with vegetables and large testicles that he said were provided from a state-run slaughterhouse.

The festival includes dishes such as testicle pizza and testicles in bechamel sauce flavoured with a variety of herbs found in the region. Visitors eat the dishes with plenty of wine or beer, and the stalls also sell roasted pig or lamb "as a side dish".

"I came here last year, and decided to come back," said Anna Wexler, an Israeli citizen originally from New York who is now a member of the festival's jury. "It was delicious. There was testicle moussaka, goulash, stallion, boar, bull and many other things."

The festival also gives prizes to those who have made the news for being "ballsy". This year one of the unsuspecting winners was Barack Obama. "He's the bravest man in the world," said Erovic. "Obama took over the world at the most difficult economic and political times. He showed he has balls."

The other prize went to the US pilot Chesley "Sully" Sullenberger, who last year glided a passenger jet into the Hudson river in New York rather than risk crashing into a densely populated area.