Ali of Kabab Cafe will make virtually any part of a sheep you ask him to, if you give him notice. He's also made me beef cheeks several times. When I had that sheep's eyeball, the sheep's cheeks were part of the whole dish. Yum. His spleen dishes are really good dish, I like it better than kidneys. And as for tongue - one of my favorite things. I made a Libyan recipe which is layers of potato slices, lemon slices, artichoke hearts, tongue, with lots of olive oil and turmeric, salt and pepper, and slow baked. Outta this world. Got it from Copeland Marks' "Sephardic Cooking."