I love meat originally covered in fish — quantity of livers? (7)
I believe the answer is:
biomass
'quantity of livers?' is the definition.
The definition suggests a singular noun which matches the answer.
'i love meat originally covered in fish' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'originally' suggests taking the first letters.
'covered in' indicates putting letters inside.
'fish' becomes 'bass' (bass is a kind of fish).
The initial letter of 'meat' is 'm'.
'i'+'o'+'m'='iom'
'iom' placed into 'bass' is 'BIOMASS'.
Can you help me to learn more?
(Other definitions for biomass that I've seen before include "Organic source of energy" , "source of 8 [RENEWABLE ENERGY]" , "Measure of living organisms" .)