I am Sephardi, and being adventurous in the kitchen I occasionally like to prepare non-standard organs: lungs, hearts, spleens, etc.
Occasionally I've had objections from Ashkenazi friends or relatives: "we don't eat hearts", "we don't eat spleens", etc.
I've done a lot of Google searching and haven't found any source that said Ashkenazim can't eat any of the above (or other internal) organs. Are there actual, known minhagim related to these? Or are my guests just making excuses to avoid eating something they find too weird?
(To clarify: I'm not referring to the laws of cutting open hearts/liver and roasting them before cooking and various other restrictions - I'm referring to a blanket prohibition.)