Banana
Bananas are a fruit beloved of the Doctor (DW: The Doctor Dances, The Girl in the Fireplace) and also a good source of potassium. (DW: The Doctor Dances)
The Doctor claimed that while partying with the Madame de Pompadour in 18th century France, he had invented the banana daiquiri several centuries early. (DW: The Girl in the Fireplace)
As the Doctor mentioned, a banana grove grew in Villengard at the former site of the weapons factories. (DW: The Doctor Dances)
In episode 1 of The Two Doctors the Sixth Doctor finds a banana whist searching his pockets for piece of wire. He gives the banana to Peri who later starts to eat it (but gives up when the sight of a dead Androgum makes her feel sick.)