I just want to add that arguing about sandwiches is wonderful and was a ray of sunshine in an otherwise bleak workday. I'm talking new born baby in detox sad, father murdered by single punch sad, grandma dealing crack instead of caring of small children in her care sad, mother of five committing suicide sad, finding out a girl I tried to help has ended up in the sex trade sad. It has been a horrible horrible work week over the past five days I have returned since our grandma's funeral. I'm kind of at my limit. Thankfully I have tomorrow off.
I was thinking about this: there are hamburger buns, and there are other buns. As I drooled over much earlier in this thread, a bahn mi is certainly a sandwich, and it is on a special Vietnamese crusty roll. I still insist that a burger is not a sandwich but I will concede that a sandwich can be on sliced bread or a bun or roll. When I think about my grandma making bread, she used the same recipe for both bread and buns, the only difference in her baking was size and final crust ratio.