... this joke takes a little bit of explanation unless you have a rudimentary understanding of Japanese. Basically, sukiyaki is a dish and daisuki means "to like a lot". So, if you really like sukiyaki and (terrible) puns, you can say "daisuki-yaki" and ... 

...

*stares in Yuko's direction* Well, I know someone who feel compelled to say it every time we have sukiyaki at her parents' house.