Seska and Chakotay sharing a bowl of mushroom soup
Mushroom soup was a type of soup whose primary ingredient was mushrooms.
It was Chakotay's favorite, and no one could cook it just the way he liked it as well as Seska. While on an away mission on an unspecified planet in 2371, Seska gathered mushrooms from a cave so she could teach Neelix how to make the soup. Predictably, Neelix wanted to "stretch" the mushrooms using leola root, but Seska and several Maquis officers concocted a plot to steal the mushrooms from the kitchen while Neelix was distracted. Seska proceeded to make the soup, which angered Chakotay when she brought it to him in private. (VOY: "State of Flux")