Preheat the oven to 400 degrees Fahrenheit.

Place bones, stew meat, onions and carrots in a large, shallow roasting pan. Rub with olive oil.

Roast in the oven for about 45 minutes, turning the bones and meat pieces halfway through the cooking, until nicely browned. If bones begin to char at all during this cooking process, lower the heat. They should brown, not burn.

Place bones, meat, and vegetables in a large stock pot. Pour about half a cup of hot water into the pan where they had been roasting and scrape up the brown bits from the pan and then transfer that to the stock pot too. Add celery, garlic, parsley, bay leaves, and peppercorns to the stock pot.

Fill the stock pot with cold water, to one to two inches over the top of the bones. Put the heat on high and bring the pot to a boil, then reduce heat to a low simmer. Cover the pot loosely and let simmer low and slow for three to six hours. Do not stir the stock while cooking.

While it cooks, sporadically use a large metal spoon to skim the fat and any scum that rises to the surface.

Pour the stock through a sieve to remove the bones, meat, and vegetables. Allow stock to come to room temperature, then chill.

Once the stock has chilled, skim the fat from the top—or bring the mixture to a boil to reincorporate the fat into the stock.