Preheat the oven to 375°F.
Layer the chicken parts in the bottom of a very large roasting pan. Roast until browned, turning halfway through roasting, about 2 hours.
Remove the pan from the oven. Add the onions, carrots, celery, and garlic and stir to mix well. Continue roasting until the vegetables soften, about 45 minutes.
Transfer the contents of the pan to a large heavy stockpot. Place the roasting pan on two burners on the stove over medium-high heat. Pour the wine into the roasting pan and stir with a wooden spoon to deglaze and dislodge any browned bits on the bottom of the pan. Pour the hot wine mixture into the stockpot. Add the tomato paste, parsley, thyme, bay leaves, peppercorns, and enough cold water to cover by 1 inch.
Bring to a boil over medium-high heat. Reduce the heat to medium-low and simmer, uncovered, for 4 hours, skimming from time to time to remove the foam that forms on the surface.
Strain through a fine-mesh strainer into a large bowl. Cool completely. Cover and refrigerate. (The stock can be refrigerated for up to three days. Or freeze in airtight containers for up to two months.)
Yield: 2 quarts