Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   2      medium        onions
   2      medium        leeks
   2      tablespoons   olive oil
   1      pound         heads and bones from red -- snapper, rockfish,
                        -- c
                        flounder -- porgy, or sea bass
   1      tablespoon    tomato paste
                        salt to taste
   2      quarts        boiling water
   1                    celery stalk
   2      sprigs        fresh thyme -- (or 1 tsp, dried)

Preparation:

PREPARATION: Peel and coarsely chop the onions. Rinse leeks, remove green tops, and reserve white parts for another use. COOKING: Heat oil in a 6-quart soup kettle. Add onions and sauté over medium-high heat until softened, about 2 minutes. Add fish heads and bones and sauté until golden, about 5 minutes. Stir in salt and tomato paste. Add the boiling water to the soup kettle. Cut the celery stalk in half and add it to the soup along with the thyme and leek greens. Simmer for 25 minutes. Strain broth through a fine sieve and return it to the soup kettle; set aside. (Can cool, cover, and refrigerate for up to 2 days or freeze for up to 1 month.) Makes 2 quarts