Choose to upset the pot (3)
I believe the answer is:
opt
'choose' is the definition.
(both can mean to pick something)
'upset the pot' is the wordplay.
'upset' is an anagram indicator.
'pot' anagrammed gives 'OPT'.
'to' is the link.
(Other definitions for opt that I've seen before include "Elect" , "Prefer, choose" , "Select as a preferable alternative" , "Pick from pot" , "Have preference for something" .)