Highlands dish given to the French (8)

'highlands' is the definition.
(plural of plateau - plateau is a bit of high land)

'dish given to the french' is the wordplay.
I cannot quite see how this works, but
'dish' could be 'plate' (plate is a kind of dish) and 'plate' is found in the answer.
'to the french' could be 'au' ('to the' in French) and 'au' is located in the answer.
A single letter 'x' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...