This is an adverb
Translation
En substance
It could be translated in "en l'essence" but only scholars would do it.
au fait
un beau geste
if you mean the phrase "mise en place" Set in place - the things you are about to cook
Carte Blanche
Tete a tete is a fairly well known French phrase. While the phrase literally translates to 'head to head', it's meaning is of a meeting or conversation between two individuals.
It is a French phrase meaning "scandalous".
double entendre - calembour
"Time is of the essence" is the correct version of the saying.
Deja is a French word meaning 'already'. Derived from the French phrase 'deja vu' meaning 'already seen'.
'Bastien' is a French first name. It has no meaning as a word.
au fait
The English verb "allot" (meaning to allocate) is "attribuer" in French. The phrase "a lot" (meaning many or much) is "beaucoup."
c'est cher is the translation in French. This is the phrase meaning expensive in French.
What is psychological essence
Que c'est is French for the phrase, "What is it?". This is actually a modified version of the French phrase, "Que est ce que ce est" meaning "What is it that it is?"
it means: 'to be fed up'
The phrase from French is "au contraire" meaning "on the contrary.