the perfect drink to accompany a black pudding is?

Hmmm, difficult one. Depends on how or when you're serving them.

I'd suggest a glass of red wine for your pear/stilton combination (sounds great, must try it). A decent cider would suit a Normandy boudin. Morcilla might be better with a dry white? For British Black Pudding, I find it hard to see how a mug of tea could be beaten.

I understand what you mean about the 'unmentionable' ingredient. One of my cousins married an American. Having inadvertently eaten Black Pudding at a family restaurant meal, he spent the rest of the day muttering: "you people really eat blood???"