Sandwiches

Throughout the series, Ryan and Brian have made frequent references to sandwiches. It is unclear whether this is an intentional throughline or simply a side topic of great interest to the hosts. Some of the more prominent discussions have included:
 * Is a taco a sandwich?
 * Is a wrap a sandwich?
 * Is a hot dog a sandwich?
 * What is a decker? (This topic, spun from a recognition that commonly named "triple-decker sandwiches" may have either three slices of bread or three layers of ingredients, has come up with such frequency that there have been video and audio responses to the "what is a decker?" question. Notably, a video was created by Eric Peterson, and later, an audio re-enactment was performed by two fans for an episode of Fill Me In.)
 * Is any ingredient between two pieces of any other ingredient technically a sandwich?