Scot happened to eat speciality European dish (8,6)
I believe the answer is:
macaroni cheese
'dish' is the definition.
(I've seen this before)
'scot happened to eat speciality european' is the wordplay.
'scot' becomes 'mac' (many Scottish surnames begin with Mac).
'happened' becomes 'arose' (I've seen this before).
'to eat' means one lot of letters goes inside another.
'speciality' becomes 'niche' (I've seen this before).
'european' becomes 'e' (abbreviation e.g. EU).
'niche'+'e'='nichee'
'arose' going around 'nichee' is 'aronicheese'.
'mac'+'aronicheese'='MACARONI CHEESE'
(Other definitions for macaroni cheese that I've seen before include "Instead of this savoury" , "food" , "melted in dish" , "Savoury pasta dish" , "dish - with 29a" .)