Sentence:  Well, for the future, when you cook another whale-steak for my private table here, the capstan, I'll tell you what to do so as not to spoil it by <WSD>overdoing</WSD>. Hold the steak in one hand, and show a live coal to it with the other; that done, dish it; d'ye hear? 
Meaning of the word marked with <WSD> tags:  To cook for too long.