Food fight
From Tardis Wiki, the free Doctor Who reference
A food fight was a fight, usually fought for fun, in which participants aimed to cover their opponents with food. Food could be thrown by hand, or launched by using cutlery as a catapult.
When she was 13, Rose Tyler had a boyfriend who she described as a "master" of food fights. In 2501, Rose put his teachings to use when she used mashed potato to instigate a food fight in the canteen of Detention Centre 6. (PROSE: The Monsters Inside)