FUN FACT: if you go to Wikipedia and search up liver and onions and you go to the references section, the 5th reference is a link to this video en.wikipedia.org/wiki/Liver_and_onions#References
My headcanon is that there's a weird infection going through Springfield that makes everyone grow a beard randomly and get thirsty for some liver with onions. It is not studied well, but possibly spreaded by tiny lollipop men and dancing ice cream cones.