Homemade Fish Stock

We went to a Portuguese restaurant for lunch and I had the most delicious seafood risotto.  We spoke with the owner and gave me the recipe for the fish stock. 

INGREDIENTS

4 lbs. Red snapper, de-scaled, gutting, and sliced
1 large leek, white and light-green parts only
2 dried bay leaves
8 sprigs fresh flat-leaf parsley
10 sprigs fresh thyme
4 whole cloves
1 1/2 teaspoons fennel seeds
8 whole black peppercorns
1 1/2 tablespoons unsalted butter
1 medium onion, cut into 1/4-inch pieces
2 medium carrots, scrubbed and cut into 1/4-inch pieces
2 stalks celery, scrubbed and cut into 1/4-inch pieces
1 cup dry white wine

DIRECTIONS

Remove the gills and any traces of blood from fish heads; thoroughly wash bones, and cut them to fit into a 12-quart stockpot. Place heads and bones in a large bowl, and set aside.

Quarter leek lengthwise; cut into 1/4-inch-thick slices. Transfer to a bowl of cold water; let stand 5 minutes to rid leek of sand. Lift out of water; drain in a colander; set aside.

bay leaves, parsley, thyme, cloves, fennel seeds, and peppercorns in a 12-inch-square piece of cheesecloth. Form a bundle, and tie with kitchen twine; set aside.

Melt butter in a 12-quart stockpot over medium heat; add cut leek, onion, and celery ; cook until vegetables are tender, 8 to 10 minutes. Increase heat to medium high, and add fish heads and bones. Cook, stirring, 5 minutes. Add wine, bouquet garni, and 2 1/2 quarts water, covering the bones. Bring liquid to a boil. Reduce heat to low, and simmer 45 minutes, skimming any scum that rises to the surface. Turn off the heat, and let sit 10 minutes.

Prepare an ice bath. Strain the stock through a fine sieve set over a large bowl. Set the bowl in the ice bath. Use stock within 1 day, or freeze for up to 3 months.