I have heard that it is Makruh to eat the liver or brain from a Halal animal that is otherwise slaughtered correctly? If so, what other parts of the animal are Makruh to eat?
It is not Makrouh to eat liver nor brain of Halal animal but it is Haraam to eat the gland inside the brain.
It is Makrouh to eat the kidney of Halal animal, as well as the veins and two small parts of meat out of the heart of the animal which are called the ears of the heart آذان القلب.
'Wassalam.