Vegemite was a type of yeast paste used as a food ingredient by Humans, originally from Australia and New Zealand on Earth.
While they were trapped in the Caeliar city of Axion and speaking of things they missed, Erika Hernandez suggested that Veronica Fletcher should have lied and said she missed something like Vegemite, but Fletcher didn't want it, despite originating from New Zealand. (ST - Destiny novel: Mere Mortals)