Fish stock (fish fumet)

Warm the olive oil and add the small-cut mirepoix.

Add the optional mushroom trimmings or slices and sweat the vegetables on low heat without browning, about 8 minutes.

Wash the fish bones well, removing blood and anything that would cloud the stock; use bones of lean fish.

After about 10 minutes add the fish bones and sweat them about 5 minutes, stirring from time to time.

Add the white wine (or the same amount of water) and simmer another 5 minutes, stirring occasionally.

Cover the bones with cold water, pushing them down so they are fully submerged.

Bring to a boil rapidly on high heat on the biggest burner, to pass quickly through the danger zone.

At the boil turn down to a low simmer and cook 30 minutes total, skimming regularly; add the bouquet garni after 15 minutes.

Turn off the heat and let infuse about 10 minutes before straining.

Pass the stock through a fine mesh, lined with cheesecloth if the mesh is not fine.

Cool the stock rapidly and refrigerate covered.

Next day lift off the congealed fat and discard it; store in containers and freeze.