The most common and most likely answer to this crossword clue is the 8 letter word RACLETTE
I've seen this crossword clue in Financial Times
R
A
C
L
E
T
T
E
Buddy explains!

The straight part
We know that "Swiss speciality" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case swiss speciality = raclette.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does RACLETTE mean?
RACLETTE noun- A dish, of Swiss origin, similar to a fondue, consisting of melted cheese traditionally served on boiled potatoes and accompanied with pickles.
- A firm cheese suitable for use in this dish.