Gratineed Ox Tongue in Mushoom Cream Sauce

Directions

1. You need to pre-boil tongue with onion, carrot and celery for about 3 hours. You then let it cool a bit (you can run it under cold water) and peel off the skin.After boiling, it should come off rather easily. Some recipes tell you to peel the tongue after 20-30 minutes of cooking, which (I suppose) allows the tongue to better absorb the aromatics and possibly cook a bit faster. Allow the tongue to cool completely and then slice horizontally as much as of it as you plan to use for your dish. (Unless you're having dinner for 8, you probably won't be eating the whole thing in one sitting!)
2. made my favorite mushroom cream sauce: thinly slice mushrooms (I used 'baby bellas' but, of course, chanterelles or some other wild mushrooms would make it even better) and saute them quickly in a mixture of olive and butter, season with a bit of salt to encourage them to render their juices. When the liquid has evaporated and the mushrooms have much reduced and are just beginning to brown (as wet heat turns to dry, you will hear the mushrooms start to sizzle) add a buttuto of shallots and parsley, mix well, and sauté for just a minute or two more. (The mushroom cooked this way are wonderful as a side dish, by the way.) Add a ladleful of rich beef broth (or stock) and let it reduce until quite syrupy, then pour in an ample amount of cream (a good cupful, at least) and allow that to reduce as well, but only until it reaches a sauce-like consistency--and a fairly thin one, too, as the sauce will reduce a bit more in the oven. Taste and adjust for seasoning.
3. Assemble your dish by lay out the tongue slices in a greased gratin dish, overlapping them slightly like so many roof tiles. Spoon over the mushroom cream sauce, making sure that the mushrooms are well distributed, then top with lots of grated parmesan cheese and dot with butter. Bake in a hot oven (200C, 400F) for about 15 minutes, until the sauce is bubbling and a nice golden crust has formed on top. You can help the crust along by browning the dish under a broiler for a few minutes at the end. (Make sure you don't reduce the sauce too much--if you're like me, you'll want enough to sop up with bread later on...!)
4. Allow the gratin to 'settle down' for a few minutes (while you're enjoying your entrée) and serve in its gratin dish. And make sure you have plenty of crusty bread to sop up that exquisite sauce.
5. NOTE: I use the mushroom cream sauce described above for all sorts of things: as a topping for ham steaks (which can be made in exactly the same way as this tongue dish), to dress egg pasta or potato gnocchi--it's my favorite sauce for gnocchi ai funghi--or, in the Austrian manner, served with the wonderful bread dumplings called knoedel or, in Italian, canederli.