Now I don't want to offend any Normans, Ninas or Nells who might be reading, but I fear that n is a negative, nasty, nasal sort of letter.
There's a terrible pessimism about n-words - not, none, nothing, nobody, nowhere, no, nay, never, no more. And as an editor of illustrated alphabet books I've found n distinctly unsavoury: a nurse in a nest, wearing a necklace of nails and needles, is not a nice image to put before little children.
It could have been so different. We could have adorned n-pages with wholesome images of noranges, naprons and numpires. But one of n's little jobs is finishing the indefinite article before words beginning with a vowel (an egg, an imp, etc) and over the centuries n has detached itself from some words and adhered to the article.
N's pronunciation presents particular difficulties for children with ear, nose and throat problems. As part of the ng phoneme (that nasal noise in words like thing and think), it is a mystery to any child who has spent the early years talking down its "dose". I've had many a note from little dyslexics proclaiming "Thack you for teaching me".
N is probably at its most interesting when silent, as in column, autumn (from Latin) and hymn (Ancient Greek). In each of these it is sounded when an ending is added (autumnal, hymnal, columnar and columnist).
But where is it in restaurateur? Spellers have every right to expect an n in this word, and only a naughty, niggly little letter would fail to turn up.