Clean the fish bones and rinse well in running water.
Fill a large heavy-bottomed pot with cold water.
Add the fish bones, roughly chopped celery, a peeled onion, a couple peppercorns, the parsley, the carrot, salt and finally all of the water.
Bring the water to a boil over medium-low heat and simmer for 25 to 30 minutes.
After 10 minutes, use a slotted spoon to skim off the foam that will form on the surface of the broth until clear.
Once the broth is done, filter it through a chinois.