i have lived in minnesota for like a year and a half now and hot dish has come up in my life exactly zero times
pretty sure it’s a myth tbh
In the 1980s my grandmother used to make something for me that she called hotdish. I remember it as basically macaroni and cheese. May have had some other ingredients, I dunno.
(Whenever I’ve read about the tradition of “hotdish” it’s always said that practically anything can get called a hotdish. Maybe the traditional foods themselves persist, but people are losing the less helpful tradition of calling them all the same name.)