Lyonaise or Lyonnaise: How To spell?
The word Lyonaise is misspelled against Lyonnaise, an adjective meaning "Applied to boiled potatoes cut into small pieces and heated in oil or butter. They are usually flavored with onion and parsley."
Lyonnaise has double "nn" is mispronounced as "n"Remember double 'NN' in between the strings lyo & aise which should not be misspelled with single 'N'
Wrong Spelling:  lyo-n-aise  Correct Spelling:  lyo-nn-aise 
Find more incorrect spellings of Lyonnaise to spell right way.