In French, it is a big one ;-) It changes the pronunciation of the word from \flɑ̃.bœʁ\ to something like \flɑ̃.be.yʁ\
They were joking--"aigu" (é) is "not grave" (è).
Hey, this is no place to circon-flexe that you know fancy names for little extra bits on letters.
This series of puns is macron me ill.
Sacrebleu!
Typo: sacré bleu!
Alternatively, flambéer or flambé-er, since by the time you're using "flambé" as a present-tense verb you're already in mangled culinary-loanword territory.