Best Chicken Stock

David Lebovitz has a wonderful recipe for chicken stock in My Paris Kitchen. The only problem is that it uses a whole chicken, which I'm seldom willing to do. Instead, I tend to keep a ziploc in the freezer for the leftover carcasses from roast chicken dinners. When I have enough on hand, I make a batch of this stock, which is fantastic. (It is also very easy to whip up the night of the roast chicken dinner, when the guests are gone and family is relaxing in from of the TV. Smells wonderful.)
For those times when making stock from scratch is not in the cards, I still recommend Better than Bouillon concentrate, now widely available.

Chicken Stock

2-2 1/2 pounds chicken carcass
3 litres cold water
1 onion, unpeeled and quartered
1 carrot, unpeeled and cut into large pieces
1 rib celery, leaves attached
1 bay leaf
a few sprigs flat leaf parsley
4 sprigs thyme
generous pinch sea salt or kosher salt
10 black peppercorns

Put all ingredients in a large pot, bring to a boil, reduce heat and simmer for 2 1/2 hours.  (Add water if necessary so chicken is submerged.)
Strain through a fine mesh strainer.  Freezes well.