There is a large Basque community where I grew up and marinated beef tongue is a favorite with them. I like it too. The tongue is first boiled and sliced very thin and then marinated in red wine vinegar, garlic, and olive oil. To get more info google Woolgrower's restaurant pickled tongue recipe.
One of my favorite places. Never had tongue there but the lamb chops were great
Had tongue in a basq restaurant in Winnemucca NV.
It was really good. Almost a gelatinous gravy on it.
