Place all ingredients in a large stockpot and cover with filtered water.
Bring to a gentle boil, then reduce heat to low and simmer uncovered for 1–2 hours.
Strain the broth through a fine-mesh sieve, discarding the solids.
Taste and season lightly with sea salt and pepper, or leave unseasoned if you plan to use it as a base.
Store in jars in the refrigerator for up to 5 days, or freeze for later use.