Cut meat into pieces and put in a large pot with enough water to cover. Salt lightly. Add peppercorns and cook, covered, till the meat easily comes off the bones. During cooking skim off foam and scum several times.
Remove meat and debone. Cut everything into ½-inch dice or small pieces. Because of the different textures you will not be able to cut it evenly.
Take fat off the broth remaining in the pot. Add garlic to the broth and boil till broth is reduced by half.
Beat the egg whites and mix into the broth. Keep stirring over heat for about 5 minutes while egg whites harden and gather the impurities in the broth. When foam hardens, remove all scum. Turn down heat to lowest and simmer for an additional 10 minutes. Strain broth through a triple layer of cheesecloth which has been rinsed in cold water.
Use individual soup plates or molds or one large mold (a pâté form or any other type). Place some of the meat in individual molds or the one large mold. Strain enough broth over meat to cover completely. After the broth cools, place it in the refrigerator to jell.