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.

The Third Doctor eating a plate of cheese sandwiches. (TV: The Sea Devils)

The sandwich was named after John Montagu, Earl of Sandwich. (AUDIO: Sabbath Dei)

References

Ace ordered "four bacon sandwiches and a cup of coffee" whilst in London during the Shoreditch Incident in November 1963. (TV: Remembrance of the Daleks)

Clyde Langer's cold chip sandwich scared Kist Magg Thek Lutiven-Day Slitheen in his disguise as Tim Jeffery. This helped Sarah Jane Smith figure out that vinegar was a weakness of the Raxacoricofallapatorians. (TV: Revenge of the Slitheen)

While hiding in the Doctor's TARDIS, Klov Dreb Fotch Passameer Day Slitheen III stole, among other food, cheese sandwiches. (WC: Who Ate All the Biscuits?)

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

While working late, Toshiko Sato made Owen Harper a cheese and pickle sandwich. (TV: Meat)

Lacking a penny, Artie Maitland gave Embassario Webley a sandwich for a chance to play his Cyberman at chess and win five imperial shillings. (TV: Nightmare in Silver)

On the day he died, Donald Babinger ate a cheese sandwich, which he shared with a pigeon. (PROSE: Apollo 23)

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 the Master'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)

The Thirteenth Doctor craved fried egg sanwiches after her regeneration. (TV: The Woman Who Fell to Earth)