I remember my mother preparing beef tongue when I was a child, simmering for hours, then skinning and pressing, before it was cut into neat slices for salads or sandwiches. I remember liking both taste and texture.
Fresh beef tongue is widely available in France and not all that expensive per kilo. I fancied buying a tongue to provide a bit of a change on the lunchtime platter. But beef tongues are enormous - 4 or 5 kilos of solid meat. You can buy half tongues, but they still put a serious hole in the weekly food budget, coming in at about 10€.
In the end I decided we would go for something smaller (and even cheaper per kilo if you buy it and cook yourself). Pork tongues are just as widely available, and lamb tongues are sometimes too.
I bought a packet of cooked pork tongue in aspic, to see if we liked it. So far as I can tell, comparing the pork tongue to my far away memories of beef tongue, they are very similar, and I will definitely be buying the occasional fresh pig's tongue to slow cook myself.