Black pudding
The short answer is that black pudding can be included provided the pigs were raised by a local farmer.
Does anyone else remember Mankinholes Youth Hostel (and Ruth Halliwell -I think - the warden) in the 1970s, where the breakfast was almost entirely local sourced and the eggs were so fresh and laden with protein that the yolks stood up in a hemisphere? Now I have to go and have a quiet nostalge.