How Is This The Answer?

[aurion]

Clue: Food is satisfactory in parts (8)
Answer: RISSOLES

WHY?????

I can see IS in the answer and ROLES as 'parts' but where does the extra S come from?

[fiction-factory]

Maybe S is an abbreviation for a Satisfactory grade

[Neveracrossword]

S - Satisfactory has come up before, I think. Homework used to have G, VG, S etc.

[aurion]

Thank you both!
:-)

[Neveracrossword]

Aurion, I couldn't find much online, but there was reference to S, satisfactory, being used in 'academic and educational contexts'

[herbage]

Yep as used by teachers but not a great clue