Popcorn

Popcorn was a type of food.

The human forms of the Gods of Ragnarok ate popcorn at the Psychic Circus. (TV: The Greatest Show in the Galaxy)

Flip Jackson used the food machine in the Doctor's TARDIS to make popcorn. (AUDIO: The Fourth Wall)

Behind the scenes
In the fourth-wall-breaking cinema intro for The Day of the Doctor, Strax says he likes popcorn because when he eats them he can hear their tiny screams. As a Sontaran he enjoys this.