Sandwich

A sandwich was an item of food consisting of two pieces of bread with a filling of some sort, originating on, although not limited to, Earth. Sandwiches of grilled meat patties encased in a bun were known as burgers. Condiments like mustard were often used on sandwiches and other "hand-held" foods.

Department Regulation 29d forbade the use of unapproved sandwiches at a picnic. (TV: Fear Itself)

The Doctor
The Second Doctor started eating a sandwich in the TARDIS whilst resting after defeating Salamander. He stopped eating it when the Great Intelligence's web started ensnaring the TARDIS. (TV: The Web of Fear)

The Third Doctor ate one of 's sandwiches during a sword fight with him. He also ate a plateful of cheese sandwiches that Captain Hart had brought for Jo Grant, leaving her only a lettuce garnish. (TV: The Sea Devils)

The Fifth Doctor claimed to have invented the sandwich. (AUDIO: Fallen Angels)

The Sixth Doctor's favourite sandwich consisted of peanut butter, lettuce and potato chips. (PROSE: Timeshare)

The Eighth Doctor, Charley Pollard, Viola Learman and Major Ferdinand made and ate sandwiches whilst being held by the Daleks in Mariah Learman's palace in New Britain. (AUDIO: The Time of the Daleks)