One way to offer mate something edible (9)
I believe the answer is:
mincemeat
'one' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'way to offer mate something edible' is the wordplay.
I cannot really see how this works, but
'way' could be 'n' (Compass direction - North) and 'n' is found within the answer.
an anagram of 'mate' is 'meat' which is present in the answer.
The remaining letters 'mice' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
(Other definitions for mincemeat that I've seen before include "Christmas pie filler" , "What did one make of the defeated" , "Tart ingredient" , "made of one that is thoroughly beaten?" , "pie-fillers" .)