Fire in accommodation starts gas oven (3,2)
I believe the answer is:
let go
'fire' is the definition.
(thesaurus)
'accommodation starts gas oven' is the wordplay.
'accommodation' becomes 'let' (I can't justify this - if you can you should give a lot more credence to this answer).
'starts' indicates taking the first letters.
The initial letters of 'gas oven' is 'go'.
'let'+'go'='LET GO'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for let go that I've seen before include "Discuss no further - dismiss - release" , "Drop" , "Don't hold on" , "Release or free" , "Release or permit to depart" .)