Wash the tongue well, place it in a pot, pour in cold water and heat. When it comes to a boil, add the carrots and onions, 2-4 bay leaves, 4-5 cloves, and a pinch of salt and pepper. Skim off any foam. After 2 hours, remove the carrot (you can do this earlier, if you want to use it to decorate the tongue). The tongue should cook for about 3.5 hours. Put the boiled tongue in cold water for a couple of minutes to make it easier to peel off the skin. Let it cool, then slice it. Add 2-3 tablespoons of gelatin to a pot and pour in the broth heated to 80 degrees and sieved (1 glass of broth per tablespoon of gelatin). Stir until the gelatin dissolves. Arrange the tongue, parsley, olives and carrot slices on a plate. Carefully top with the broth and place it in the fridge to gel. Serve with mayonnaise.