Preheat oven to 425°F.

Using two large roasting pans, spread out 4 drumsticks in each pan then fill in the gaps with the veggies. Drizzle the olive oil evenly over the ingredients and mix until well coated. Season lightly with salt & freshly ground black pepper.

Roast in the oven for 60 minutes or until lightly browned, turning occasionally.

Transfer the ingredients to a very large stockpot (16-to-20 quart) and place it on the cooktop. Add the parsley, thyme, bay leaves, tablespoon of salt & peppercorns. Cover with 10 quarts of water and bring to a boil.

Lower the heat and simmer uncovered for a total of 6 hours, skimming off any foam that may float to the top.

After simmering for 1 hour, carefully remove the drumsticks with long-handled tongs and place them in a large pan. Once cool enough to handle, remove meat from the bones and set aside to be saved for future use. Place the turkey bones back into the stockpot to simmer for the remaining time.

When the stock has simmered for a full 6 hours, remove from the heat. Strain the entire contents of the pot through a micro-mesh colander and discard the solids.

Pack in containers and chill overnight. Refrigerate for up to 5 days or freeze for up to 3 months.