French food ordered in Sanssouci (9)

I believe the answer is:

saucisson

I'm a little stuck... Click here to teach me more about this clue!

'french food ordered' is the definition.
I know nothing about this answer so I cannot judge whether this works.

'sanssouci' is the wordplay.
'sanssouci' can be anagrammed to 'SAUCISSON'.
But, I'm unsure how this is indicated.

'in' acts as a link.

Can you help me to learn more?

I've seen this clue in The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.