Snap the bones from one roasted chicken into pieces and place it in the middle of the slow cooker. Roughly chop the 1 large onion, 2 stalks of celery, 2 large carrots, 1 head of garlic and scatter them around the chicken. Add the 2 bay leaves1 cup fresh herbs, and 1 teaspoon black peppercorns.
Add enough water to cover the chicken bones. Approximately 12 cups water. Slow cookers can be filled to within an inch of the top.
Cook for at least eight hours on low. Eight hours is the minimum amount of time I would cook the stock. I recommend at least 12 hours. 24 hours would be even better.
Set a colander over a large bowl. Using tongs and a slotted spoon, transfer the large bones and vegetables from the slow cooker to the colander. After the large pieces have been removed, pour the remaining stock through the colander and into the bowl. Discard the scraps and season the broth with salt.
Let the stock cool to room temperature, then transfer it to storage containers and refrigerate. As the stock chills the fat will rise to the surface and solidify. Use a spoon to skim the fat off the top of the broth.
Notes
Remove as much meat from the rotisserie chicken bones as possible.Add chicken feet to your bone broth they will increase the amount of collagen released into the broth.Use whatever vegetables and aromatics you have on hand.For clearer stock, clean out your strainer and line it with a coffee filter or cheesecloth. Strain the stock again.Allow broth to cool completely before refrigerating or freezing.Storage: The easiest way to store chicken stock is to freeze it. Allow the chicken stock to cool and then pour it into ice cube trays. Once the stock has frozen, store the chicken stock cubes in an air-tight container labeled with the date and contents.Freezing chicken stock in an ice cube tray makes it easy to portion out just the right amount.