Rinse tongues, scrape, soak in cold water. Boil for 1.5-2 hours with onions, carrots and spices. Add salt at the end of cooking.
Immediately dip the boiled tongues into ice water and remove the skin.
Strain the broth, cool, add gelatin. Heat the broth, but do not boil, and stir until the gelatin is completely dissolved.
Finely chop the tongues, put in a mold, add lemon slices, pickled mushrooms, pour over the broth and put in a cold place to harden.