Hi Allen. This is your favorite Hamburger Bento. I have uploaded upon your request. :D At Cafe Japan, we use both beef and pork for the hamburger. We have to say sorry that both of customers who can not eat beef and pork though we would like to say it is a secret of our recipe. It is said that there is a difference of the temperatures melting each beef's and pork's fat and its combination create the taste of hamburger. In Japan, there are a number of hamburger restaurants though the each chef and restaurant creates their own recipe. We have also experimented to change the ratio of beef and pork and finally made our own recipe. Hamburger Bento and Hot hot hamburger on the iron plate at the restaurant has each different recipe each and used different kind of sauce to make them more tasty.:> I think there are homemade hamburger recipes at each house in Japan.