Go with a fresh essence (10)
I believe the answer is:
peppermint
'essence' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'go with a fresh' is the wordplay.
'go' becomes 'pep' (I've seen this in another clue).
'with' means one lot of letters go next to another.
'a' becomes 'per' (eg 'one a day' means 'one per day').
'fresh' becomes 'mint'.
'pep'+'per'+'mint'='PEPPERMINT'
Can you help me to learn more?
(Other definitions for peppermint that I've seen before include "herb" , "Sweet flavoured with aromatic oil" , "Pungent sweet" , "Aromatic plant" , "flavour" .)