If using raw bones, blanch them first: place bones in a large pot and cover with cold water. Bring to a rolling boil for 5 minutes, then drain and rinse the bones under warm water to remove scum. Rinse the pot as well. This step yields a clearer broth. If using leftover roasted carcass, you can skip blanching.

Build the broth

Return the cleaned bones to the pot and add 8 cups cold water. Add the halved onion, chopped carrot, celery, smashed ginger, and smashed garlic. Add the bay leaf and peppercorns.

Simmer gently

Bring the pot slowly to a simmer over medium heat. As soon as small bubbles begin to break the surface, reduce heat to low so the liquid maintains a gentle simmer (not a boil). Skim any foam or fat that rises to the surface with a ladle for the first 20–30 minutes to keep the broth clear. Simmer uncovered for 1.5 to 2 hours for a light, clean broth (up to 4 hours for a richer flavor).

Season and finish

After simmering, remove from heat. Strain the broth through a fine-mesh sieve lined with cheesecloth into a clean container to remove solids. Discard solids. Stir in 1 teaspoon kosher salt and 1 teaspoon soy sauce or fish sauce, tasting and adjusting seasoning as needed (add more salt in 1/4 tsp increments if desired).

Clarify (optional for very clear broth)

If you want an extra-clear broth, use a quick clarification: whisk together one egg white with 1 tablespoon cold water per 8 cups of broth, stir into simmering warm (not boiling) strained broth, bring to a very gentle simmer for 5–7 minutes while the egg proteins coagulate and trap particles, then strain again through cheesecloth.

Serve or store

Ladle the hot broth into bowls and garnish with sliced scallions and chopped cilantro or parsley. This side broth can be served alongside main dishes, used to warm bowls, or sipped as a palate cleanser. Cool completely before refrigerating in a sealed container for up to 3–4 days or freeze up to 3 months.