Place the chicken in large stockpot. Add about 2½ quarts of water (your chicken should be just submerged, so add more if needed). Add all veggies, herbs and seasoning. Bring to a boil. Reduce to a simmer; continue to simmer uncovered for 4 hours.
Strain the entire contents of the pot through a fine sieve and discard the solids. Pour the liquid into a bowl, cover with plastic wrap and refrigerate overnight.
The next day, use a spoon to remove the layer of fat that has solidified on the top of the bowl of stock. The stock itself may become jelly-like when it’s chilled. Once it comes to room temperature again (or is heated), it will turn back to a liquid state.
Notes
The more chicken meat that is left on your carcass, the richer the chicken flavor will be in your stock.
Homemade stock will keep just fine in the refrigerator for up to 5 days. Cover and freeze for up to 6 months.