Tolerate mushroom in a cassoulet on vacation (6)
I believe the answer is:
accept
'tolerate' is the definition.
(accepting is a kind of tolerating)
'mushroom in a cassoulet on vacation' is the wordplay.
'mushroom' becomes 'cep' (name for Boletus edulis - an edible mushroom).
'in' is an insertion indicator.
'on vacation' suggests removing the centre (after the inside letters have vacated the word).
'cassoulet' with its middle taken out is 'ct'.
'a'+'ct'='act'
'cep' put within 'act' is 'ACCEPT'.
(Other definitions for accept that I've seen before include "Take on; tolerate" , "Receive something offered" , "Welcome" , "Put up with" , "Consent to receive" .)