Preheat the oven to 425 degrees F. Scatter the carrots, onion and celery over the bottom of a large roasting pan. Rinse bones and pat bones and/or meat dry. Place dry bones/meat on top of the vegetables.

Roast, turning the bones once or twice, for 1 hour, or until the bones are well browned.

Using tongs, transfer the bones and vegetables to a large stockpot. Put aside any fat from the roasting pan. Add 2 cups filtered water to the pan and bring to a boil over medium heat, deglazing the pan by scraping up the browned bits from the bottom. Add this liquid to the stockpot, along with the rosemary and parsley. Add lemon juice/vinegar plus 10 cups cold water, or enough to cover the bones, and bring slowly to a boil. As soon as the stock begins to boil, reduce the heat so that it simmers. Using a soup ladle, skim off any scum that has risen to the surface. Add the peppercorns and simmer, uncovered, for 5 hours or until meat is tender, skimming from time to time. Some of the best broth is simmered for 12+ hours.

Strain the broth through a sieve into a large bowl. Discard the debris left in the sieve, and cool the stock. If you are not planning to reduce the broth, add about 1 teaspoon of sea salt.

Refrigerate the stock for 6 hours, to overnight, to allow the fat to rise to the top and the debris to sink to the bottom. Remove the fat before using and discard debris. Divide into 1 cup quantities and refrigerate up to 3 days or freeze for up to 6 months.