In summer are roasts not cooked as much? (5)
I believe the answer is:
rarer
'not cooked as much?' is the definition.
(eg in the cooking of steaks)
'in summer are roasts' is the wordplay.
'in' says the answer is hidden in the clue.
'RARER' is hidden within 'summer are roasts'.
(Other definitions for rarer that I've seen before include "More scarce or uncommon" , "(Of meat) less cooked" , "Thinner" , "steak may be wanted thus?" , "More unusual" .)