While this recipe may not appeal to everyone, let me tell those who are adventurous enough to consider trying ox tongue that this piece of meat has a uniquely tender texture that you simply won't get from any other cut of beef. Done right, it really is melt-in-your-mouth tender.
Some people swear against the odd odor that ox tongue gives off in a dish – a fact that I can only blame the cook for. It certainly has a game animal-like smell, but is something you can work around on. I know a lot of home cooks who use a vinegar rinse to put this smell off and it does work. However, the vinegar also leaves a slight sour note on the meat which may not work well with some specific types of sauces, like the cream sauce that we'll be doing for this recipe.
So here's how I do it. I stud the underside of the ox tongue with sticks of cloves. Not only does it neutralize that distinct smell of ox tongue, it enhances the meat's flavor too.
Get the ox tongue into your slow cooker with some onions, bay leaves, black peppercorns, and salt. Leave it to tenderize for about 8 hours. To check if you've cooked it tender enough, insert a metal skewer into it – you should feel no resistance at all.
Next, take the tongue out and leave it to get cool enough to handle. Peel that tough leather-like skin on the outside. Again, if you've cooked it enough, you should be able to do this task simply by hand.
Cut the peeled ox tongue into thin slices, going against the grain – that would mean making your cuts from the tip of the tongue going all the way to the other end.
Now for the sauce. Melt some butter in a pan and sautee some finely chopped shallots and some button mushrooms. Do not substitute butter with any other oil. We're building a cream sauce and the richness of butter is what we're after.
After the shallots have caramelized a bit, dust your pan with flour. We're basically making a roux that would give body to our sauce. Roast the flour a bit to get rid of that ‘floury' taste and to give the sauce a deeper brown color.
Whisk in brown beef stock. Do not use the broth left in your slow cooker again to keep that odd smell of ox tongue from getting into your dish. Also, make sure that you're beef stock is cold or at least at room temperature to keep the sauce free from clumps of flour.
Put the slices of ox tongue into the sauce and give it at least five minutes of simmering to take on those flavors.
Just before serving, whisk in some heavy cream. Get the cream heated enough without bringing it to a boil to keep it from splitting. Finally, refine the sauce with a few nuggets of cold butter and a final seasoning of salt and pepper.