Wash the chicken thoroughly with cold water, place in an 8-quart or larger stockpot, and add the onion, celery, carrots, garlic, and cold water. Bring to a boil, immediately reduce the heat to a slow simmer, and skim away any foam, excess matter that rises to the top, or fat that floats to the top.

Add the peppercorns, bay leaves, parsley stems, salt, thyme, basil, and oregano. Cook at a slow simmer for 4 to 6 hours, uncovered, periodically skimming away fat and proteins that rise to the top. Do not stir the stock at all. After cooking, strain through a fine-mesh strainer, taking care not to disrupt the stock by mixing or by moving the chicken around. A second straining through cheesecloth will result in an even clearer stock, and chilling will cause any remaining fat to congeal at the top, making it easy to remove.