But what about open faced sandwiches? And cutting a burrito in half lengthwise (admittedly a dumb thing to do, but hey it's a thought experiment) would make it fit that definition of a sandwich as well. I do like where you're headed though, and I think we can definitely work with the idea that the way the bread is applied is important to what we consider a sandwich. I certainly think that it has to be a flat piece (or pieces) of bread on which the set of ingredients are applied. Your definition brings to light something I was playing around with as well: the idea that sandwiches are more defined on how they look than how they're actually made. Thus a sandwich could be anything that is surrounded by flat (or relatively flat) objects of the same general materials. However, this begs the question of what multidimensional sandwiches would look like (which is a super weird thing to thinks about).