What is a stoat sandwich

A stoat sandwich seems to be a sandwich made from an animal called a stoat. It’s a carnivorous mammal of the weasel family.

A stoat sandwich is a sandwich made from a stoat.  A stoat is a small weasel.  Stoat sandwiches I think were made in England at some point.  One of the Harry Potter books had Hagrid offering a stoat sandwich.