pizza Bismarck

Last week I found a good italian restaurant nearby Tokyo Dome. There are loads of italian restaurants and trattorias round my office. However they serve only spaghetti in lunch time. I really wanted to eat a pizza or other pasta such as penne. Finally I found the restaurant which serves a good pizza. The speciality is pizza Bismarck. The feature is an egg at the centre of the pizza. It was very tasty and I had a question, why is the pizza called Bismarck. Later I checked it on the internet. I could find a page written about it. According to the page the first German chancellor Bismarck used to like eating eggs. However I could not find the relation to pizza. It seems that a pizza and the german name do not have any relations. I think pizza Bismarck is not so popular in Japan. How is it in other countries? The origin of the neme is my big concern for the time being.