I have put this in food and drink as well, did you see Michelle Collins arguing about shepherds pie and cottage pie, I agree with Gordon, shepherds pie has Lamb which I don't like so won't eat adn cottage is beef which I love. which do you prefer?
I only eat cottage pie because I don't like lamb! And Gordon was right, regardless of what Michelle's mum used to call it! (the clue's in the title - Shepherds look after sheep!)
The difference has always been the meat content - 'cottage pie' - eaten by farmers who live in the towns and have access to beef, 'shepherd's pie' for the shepherds out on the hills who have access to lamb and mutton.