Lasagna filling (7)
I believe the answer is:
ricotta
'lasagna filling' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ricotta that I've seen before include "One soft cheese" , "Read the riot act about the cheese" , "Italian 8 across" , "cheese, Italian style" , "Soft white cheese used in Italian cooking" .)