Roast chickens at 350°F (180°C) for 1.5 hours, flipping halfway.
Separate the meat from the bones.
Toss bones into a large pot.
Add onion, carrots, garlic, apple cider vinegar, and water and salt.
Add turmeric and Italian seasoning if desired.
Bring to a boil, then reduce to a low simmer.
Cook for 6-10 hours.
Once it reduces to about half, strain out the bones and veggies.
Store the broth in jars and refrigerate overnight.
