Cut chicken drumsticks with meat cleaver (into 2 inch pieces); this step facilitates the release of the bone marrow into the stock giving you a rich and nutritious stock (if you don't have a meat cleaver you can skip this step but you won't get the maximum amount of collagen)
Heat 2 tablespoons of oil in large pot over medium high heat and then lightly brown chicken on both sides (do this in two batches if necessary). When lightly browned, remove chicken from pot and place in a large bowl.
Next, place onion in the now-empty pot and cook until soft, about 3 minutes. There should be fat in the pot from cooking the chicken, but you can add 1 tablespoon of oil if needed
Return chicken to the pot with the onions along with any juices that may be in the bowl, turn heat to low, and cover pot. Simmer on low for 20 minutes to allow chicken to release its juices.
After simmering, add water, salt, and bay leaves to the pot and then bring to a boil. Then immediately turn the heat down to a gentle simmer and cover the pot to prevent evaporation.
Optional: if you would like to add chicken breast meat to your stock, add it now.
After 20 minutes of gentile simmering, strain the stock carefully through a fine mesh strainer into a large bowl. Do you this is two batches if necessary or remove the large pieces of meat to make this easier.
Let the stock sit for about 10 minutes and then skim fat from top. I like to refrigerate overnight which produces a fat cap that can very easily be skimmed off.