Lilia’s favorite food is listed as “tomato juice,” which has been referenced repeatedly in the game.
During the Cloudcalling event, however, Vil asks, “…Do you actually even like tomato juice, or do you just want to consume things that are red?” and Lilia responds, “Who can say?”
There is a reference to Lilia enjoying what is possibly another red juice during Book 7: dazberry juice. Lilia says, “Back in my day, I’d chug an entire cask of this stuff at parties.” Ace asks, “How can you be THAT hype over juice?,” but the color of the juice was not confirmed.
Also during the Cloudcalling event the EN-server version of Lilia claims that the pastry “elephant ears” are one of his favorite foods, but this is untrue: in the original game he is describing “onsen eggs,” which he also does not say are one of his favorites. His original line is closer to, “they’re a specialty of mine.”