Vichyssoise
Describing something that is pretentious. When something is described as being of or having a high-class origin but is in fact mundane or common... or bad... Vichyssoise is just potato soup served cold, which is nasty and the french name just attempts to hide that. Like the phrase: "Jena se qua" instead of just saying "I don't know" or cold potato and leek soup.
"I use my initials as my name in conversations and correspondences because it sounds so much more Vichyssoise" or "Oh look at these artisanal crackers... my how Vichyssoise"