Slightly cooked (4)
I believe the answer is:
rare
'slightly cooked' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for rare that I've seen before include "Very, very occasional" , "Might steak be" , "like Ben Jonson, Jack Young thought" , "Scarce as hen's teeth!" , "Still red inside (as hens' teeth?)" .)