- 2 leeks, trimmed and carefully washed
- 4 lb. fish heads (gills removed), bones and trimmings
- 2 yellow onions, sliced
- 2 carrots, sliced
- 2 celery stalks with leaves, sliced
- 6 fresh parsley sprigs
- 3 fresh thyme sprigs
- 1 bay leaf
- 4 quarts water
- Salt, to taste
Over low to medium heat, slowly bring the liquid to a simmer, regularly skimming off the scum that rises to the surface until no more forms. Cover partially and continue simmering gently for 30 to 40 minutes, skimming occasionally.
Line a strainer with a double layer of dampened cheesecloth and set it inside a large bowl. Pour the contents of the pot into the strainer. Discard the solids. Season with salt and let cool to room temperature. Cover tightly and refrigerate. Stock may be refrigerated for several days or frozen for up to 6 months.