Step 1

Preheat oven to 400 degree F (200 C).

Step 2

Spread the poultry bones on a large baking pan. Drizzle with the vegetable oil. Toss with a spatula until the bones are evenly coated with oil.

Step 3

Bake until the bones are nicely charred, 30 to 40 minutes. Remove baking pan from oven and stir the bones once in the middle of roasting.

Step 4

Transfer all the bones to a large pot. Pour hot water onto the baking pan. Use a spatula to scrape off the brown bits and pour the liquid and brown bits into the pot. Add water to cover bones by 1 inch.

Step 5

Heat over medium high heat until boiling. Add leek and ginger. Cover, turn to medium low heat, and boil until the meat starts to fall off the bones, 3 to 4 hours. If there is still a lot of liquid left, turn to medium heat and boil, uncovered, until only 4 cups of broth remain. The stock will have turned an opaque light brown color by this point.

Step 6

Remove and discard all the solid content and drain the soup. Store in airtight container(s) in the fridge for up to 2 weeks or in the freezer for up to 3 months.