Food making gas rise within passage (7)
I believe the answer is:
lasagne
'food' is the definition.
(lasagne is a kind of food)
'gas rise within passage' is the wordplay.
'rise' says the letters should be written in reverse.
'within' is an insertion indicator.
'passage' becomes 'lane' (I've seen this before).
'gas' written backwards gives 'sag'.
'sag' placed within 'lane' is 'LASAGNE'.
'making' acts as a link.
(Other definitions for lasagne that I've seen before include "Type of pasta" , "Italian food" , "Pasta served in strips" , "Layered pasta dish" , "Italian cooking" .)