Loses race to cook dish (9)
I believe the answer is:
'dish' is the definition.
(casserole is a kind of dish)
'loses race to cook' is the wordplay.
'to cook' is an anagram indicator.
'losesrace' is an anagram of 'CASSEROLE'.
(Other definitions for casserole that I've seen before include "Meat dish" , "Make a stew" , "Cook slowly" , "meal" , "So cereals may be used for this oven-cooked covered dish" .)