Take the veal tongue out of the fridge in good time and let it come to room temperature. Place in a saucepan with the vegetables and enough water to cover the tongue completely. Bring to the boil and simmer over a very gentle heat for about 2,5 hour.

In the meantime, preheat the oven to 200°C (392°F) top/bottom heat, grease a baking dish with 1 tbsp butter. Layer the potatoes in, place the garlic in between and season everything well with salt and pepper. Bring the cream to the boil, pour over and sprinkle the gratin with cheese. Finally, spread the butter in flakes over the top. Cook for approx. 45 minutes on the lowest rack, cover if necessary.

Insert a skewer into the veal tongue to test for doneness. If it penetrates easily, the meat is tender. Then remove, rinse in cold water, pat dry and peel off the white skin. Put the meat back into the stock. Remove about 250 ml of the stock.

Melt the butter in a saucepan. Sweat the flour in it for about 2 minutes. Gradually add the stock and cook until it thickens. Finally, add the Madeira and season the sauce with salt and pepper. Stir the butter flakes into the no longer boiling sauce for a nice sheen. Cut the veal tongue diagonally into thin slices and serve with the sauce. Serve with the gratin.