Don't let the looks freak you out. The results are well worth the effort.
One large beef tongue
Trim the fatty bits off. A large chunk on the base and a couple long thin bits along the sides. You do need a razor sharp knife for this. You can skip this part all together and boil it just as it is, but I find it makes for better results if you do remove at least the big chunks of fat.
Plunk it in a large boiling pot of water with one large white peeled onion 6 bay leaves and 2 table spoons of salt. Bring it to a boil, cover, reduce to a simmer and let it go for two to two and a half hours.
After about two and a half hours remove and let it cool for about a half hour.
Remove and reserve the boiled onion. Save the broth as it is good for a soup later.
Once cool enough to handle cut the tongue in half . . .
. . . and peel the outer hide off the thing. The underside is thinner and a bit trickier to remove. Just keep at it you'll figure it out.
When done it should look like this.
Slice it in to nice half inch thick slabs
Puree the cooked onion in a blender or food processor
Melt a third of a stick of butter
Add one teaspoon each of Curry powder, Tumeric and Cumin. Pour in your blended onion adjust flavor with salt and pepper. This part you can play with. I like mine mild but if you like the hot stuff you enjoy twice, knock yourself out.
Toss in the slices and warm them up
Serve with white rice and a side veggie. . . . takes a bit of effort but it is really delicious and well worth the trouble.