Just Wondering...

I just returned from a quick shopping trip at the next-door-neighbor Migros grocery store (chewing gum and toilet paper), and I happened to notice that they sell chicken stomachs in the freezer section. After a quick Google search, all I could come up with preparation-wise was grilling them on skewers with hearts, livers and other chicken parts.

Does anybody out there know a culinary use for chicken stomachs? Stock? Gravy? Some secret Swiss recipe?

Just wondering...