1. Prosciutto
    Not proscuitto
  2. Mascarpone
    Not marscapone
  3. Lasagne
    Not lasagna
  4. Jalapeño
    Not jalapeno
  5. Habanero
    Not habañero
  6. Salame
    Not salami, unless you are referring to more than one
  7. Sauté(ed)
    Not saute(ed)
  8. Wiener
    Not weiner
  9. Espresso
    (Not expresso, for the love of god)
    Suggested by @RochelleBilow
  10. Focaccia
    Foccacia, Focacia, Focachia, Focacha...
    Suggested by @Suryamayi
  11. I haven't seen it as a spelling mistake but I've had to use all my self control to not injure several people who have said 'victorian sponge' out loud (Victoria sponge)
    Suggested by @ellaellakennedy
  12. hors d'oeuvres
    definitely not "orderves"
    Suggested by @kirkland
  13. Café con leche
    Not cafe con lychee. Also see: café au lait (not café olé!)
    Suggested by @Veronique
  14. Caesar salad
    Not Ceaser or Ceasar or Caeser
    Suggested by @amieshmamie
  15. Macaron
    Not macaroon, which is something else entirely.
    Suggested by @totallyjudged
  16. Portobello mushroom
    Not portabello or portabella
  17. Compote I once saw a room service menu that offered fruit composte.
    Suggested by @LiveandLetDi
  18. Horse d'eouvres
    It's horse divorce idiots
    Suggested by @annakomi