Roasting outside oven (4)
I believe the answer is:
oast
'oven' is the definition.
(type of kiln)
'roasting outside' is the wordplay.
'outside' indicates the answer is hidden within the clue (a word is around or outside the answer).
'OAST' is hidden within 'roasting'.
(Other definitions for oast that I've seen before include "Oven for hops" , "Kiln for drying hops or malt" , "Hop-drying kiln" , "Cooker" , "Hop-drier" .)