Salt the inner cavity of the chicken lightly and put it into a large pot of cold water. Turn the flame to medium and bring the chicken to jut under a boil Skim off any debris that rises to the surface and when the broth is clean, turn the pot to a simmer and poach the chicken until it is cooked through, somewhere around an hour / an hour and a half.
 
Remove the chicken from the pot and allow it to cool enough to handle. Clean the chicken, discarding the skin and reserving the meat for another use. Return the bones to the pot, add the vegetables and bring the pot to a simmer. Skim the broth well to remove any debris or grease and then add the peppercorns, parsley stems and bay leaf and simmer the broth until it is flavorful / you can just begin to taste the vegetables.
 
Strain the broth; discard the solids wipe out the pot of any grease or debris. Return the broth to the pot, add salt as needed and reduce until the flavors are well integrated, skimming as needed. Strain the broth through a chinoise or double layer of cheesecloth and chill immediately.