A jerkin was also a type of shirt or jacket worn by men around three or four hundred years ago, so maybe he is suggesting cooking Americans in their jackets, perhaps by baking them? In which case I recommend pricking them with a fork or somesuch, else they're liable to burst.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'