Partial to posh, European dish (6)
I believe the answer is:
fondue
'dish' is the definition.
(fondue is a kind of dish)
'partial to posh european' is the wordplay.
'partial to' becomes 'fond' (I've seen this before).
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-U).
'european' becomes 'E' (abbreviation e.g. EU).
'fond'+'u'+'e'='FONDUE'
(Other definitions for fondue that I've seen before include "Melted cheese dip" , "Dipping sauce" , "Melted cheese dish from Switzerland" , "Cubes cooked in hot oil and dipped in sauces" , "Saucy dish" .)