Cut the chicken bones into big chunks. Place in a big pot and cover with water. Bring to the boil and cook for about 15 minutes. Remove impurities.
Meanwhile, cut the onion into 4 quarters. Peel and wash the other vegetables. Cut them into big chunks. When the water is clear, add the vegetables , herbs and seasoning into the pot.
Bring to the boil then simmer for 2 hours. Remove impurities if needed.
Remove the bones, vegetables and herbs. Strain and refrigerate. The fat will get solid and easy to remove.