• 1 tablespoon unsalted butter
• 1 onion, chopped
• 2 quarts cold water
• 2 pounds goose, duck, or turkey bones, coarsely chopped
• 4 carrots, chopped
• 1 cup chopped celeriac
• 2 bay leaves

Heat the butter in a large pot over medium heat. Add the onion and sauté for 5 minutes, or until soft and golden. Add the water, goose bones, carrots, celeriac, and bay leaves and bring to a boil; with a large spoon, skim off the foam that forms on the surface. Reduce the heat and simmer gently for 1 hour and 15 minutes.

Line a colander or sieve with cheesecloth and strain the stock into a bowl or other container. Cover and refrigerate until ready to use.