The most important part is to rinse the inside of the chicken under cold water. You must remove all the liver and any other brown material. This will ensure after your skimming to remove the scum at the initial simmer, you will get a good clear soup-not schmutzy (shmoot-zee), which is ok but not as nice a clear soup.
In a large pot bring the chicken, water and salt to a simmer over high heat. Reduce heat and let simmer for 15 minutes, skimming off any scum that comes to the surface. You can use a fine mesh skimmer or a slotted spoon works fine. Stir the chicken once or twice during this process which will loose the schmutz for skimming. When you start getting only white foam, add carrots, celery, parsnip, leek,onion and black peppercorns. Simmer, uncovered,very gently, but steadily, for 3 to 4 hours. Add the parley and the dill in the last 30 minutes, or you will get green soup. Remove from heat and cool to tepid. Refrigerate overnight.
Remove most of the chicken fat that has hardened on top of the soup. Strain the soup through a large colander into another pot. Pick out any parsnip or carrots you may like to serve with the soup and discard your solids. In years past, the chicken was so flavorful that the meat was still delicious, but todays chicken, not so good. Mine as well pitch it. Reheat soup and serve as a clear broth or you can cook some noodles separately and add or for the ultimate experience, add matzo balls (Knaidlach). Will have a recipe you can follow for that, just search for Knaidlach.