...an old one but worth an airing I think:
"In search of the real Spain I visit a restaurant near a bull ring just outside Madrid. I asked for the Special of the Day and I'm presented with two large meat balls, roasted potatoes, onions and peppers in a rich sauce. It was fantastic. I asked what I had just eaten and the waiter explains they were the testicles of the losing bull from that day's bull fight!
I was so impressed that I went back a few days later and ordered the same meal but was so disappointed with the size of portion I was served that I complained. The waiter explained, "but, Senor, the Matador ee no always ween"