Hot dish, uncooked part (7)
I believe the answer is:
rarebit
'hot dish' is the definition.
(toasted dish)
'uncooked part' is the wordplay.
'uncooked' becomes 'rare' (as in a rare steak).
'part' becomes 'bit' (both mean a piece of something).
'rare'+'bit'='RAREBIT'
(Other definitions for rarebit that I've seen before include "Savoury dish of cheese on toast" , "Dish of grilled cheese on toast" , "Welsh food?" , "Arbiter of traditional Welsh dish" , "Cheese/toast savoury" .)