1 whole (fresh) chicken or leftover chicken parts.. Or a whole frozen chicken (thaw it safely!)
5-6 quarts water (A bit more or less doesn’t matter, since you can reduce the stock to the intensity level you want, anyway).
Vegetable and herb trimmings (Use what ever you have - such as ends from onions, cores and scraps from bell peppers, celery leaves, herb stems, asparagus throwaway stalks ends, fennel leaves, etc.)
Put all the ingredients in a big pot.
Bring to a boil, then reduce to a medium simmer.
After about 30 minutes, take the chicken out. That's something nice about homemade chicken stock.. it comes with chicken!
Continue to simmer the rest for an hour. (simmer longer for a more concentrated stock)
Drain it out, compost the veggies, and add salt and pepper to taste!
Let the stock stand in the fridge overnight if you're not going to use it right away.. then you can easily skim the fat off the top.