A pound off, pack with egg and pastry (4)

I believe the answer is:

filo

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

'pastry' is the definition.
(I know that filo is a type of puff pastry)

I don't understand the remainder of the clue.

(Other definitions for filo that I've seen before include "Thin flaky pastry" , "A type of very thin pastry" , "Tissue-thin sheets of pastry" , "Pastry used for baklava" , "Pastry made in thin sheets" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app