Cheese may be everything -- and nothing in mostly damp environment (8)
I believe the answer is:
halloumi
'cheese' is the definition.
(I've seen this before)
'be everything and nothing in mostly damp environment' is the wordplay.
I cannot quite understand how this works, but
'everything' could be 'all' (all things) and 'all' is found within the answer.
'nothing' could be 'o' (looks like zero - 0) and 'o' is present in the answer.
'be' could be 'hum' (humming is a kind of being) and 'hum' is located in the leftover letters.
A single letter 'i' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'may' is the link.
Can you help me to learn more?
(Other definitions for halloumi that I've seen before include "Cypriot goat's or sheep's milk cheese" , "Cheese from Cyprus" , "Traditional Cypriot cheese" , "Greek dish of fried goat's cheese" .)