Rinse bones under running cold water. Use the 2 T butter to grease a 3 gallon pot (like you would a baking dish before baking), add the leek, celery, onion, bay leaves, peppercorns, parsley, and garlic cloves. Place the bones on and cover the top with a circle of parchment or brown paper and cook slowly over low heat for about 5 minutes. You’ll be able to tell that you are ready to go with the wine when the bones turn white or opaque.

At this point, add the wine and bring to a simmer before adding water to cover all of the ingredients (should be about 2 gallons).

Bring to a simmer and continue for 60-90 minutes skimming off any scum that rises to the top. Taste test to make sure you’ve incorporated enough flavor into the stock, but don’t leave on for too long, you don’t want everything to fall apart and cloud your liquid.

When finished, let stock cool in the pot for 1 hour before slowly straining and discarding the solids. With fish fumet, I recommend you strain the liquid itself twice more through cheesecloth.

Refrigerate, freeze or utilize.