Energy old President gets with one sausage (9)
I believe the answer is:
pepperoni
'one sausage' is the definition.
(I've seen this before)
'energy old president gets' is the wordplay.
'energy old' becomes 'pepi' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'president' becomes 'peron' (I have seen 'Argentinian president ' mean 'peron' so perhaps 'president' could also mean 'peron').
'gets' is an insertion indicator.
'pepi' enclosing 'peron' is 'PEPPERONI'.
'with' is the link.
Can you help me to learn more?
(Other definitions for pepperoni that I've seen before include "what may be called a banger" , "something spicy" , "Hard, spicy beef and pork sausage" , "Spicy salami" , "Highly-seasoned sausage" .)