Combine the chicken feet, onion, leek, celery, carrots, peppercorns,
thyme,
parsley, bay leaves, and wine in a large, heavy stockpot. Cover the chicken feet with the water. Bring to a boil over medium-high heat, then immediately decrease the heat to medium-low, cover, and simmer for 8 to 12 hours, adding water as necessary to keep the feet submerged. From time to time, skim away any scum that might rise to the surface.