Chicken Stock

Carcass, wings, and feet (if the chicken comes with them) of one chicken
1 large yellow onion, unpeeled and cut in half
1/2head of garlic, unpeeled (halved horizontally)
2medium carrots, peeled and cut into chunks
2 celery stalks, cut into chunks
2 sprig thyme
1 bay leaf
1 tablespoon black peppercorns
Salt to taste