Clean the fish bones

• In a large bowl, place the bones (fish heads) and cover with cold water. Add a couple tablespoons of salt and stir to dissolve. Soak the bones for 30 minutes, drain and rinse under cold water to remove all signs of blood.
• Heat a large stock pot over medium heat, add oil and when the oil gets hot, add the onion, carrots, leek, celery and garlic. Saute until the vegetables soften, about 3 minutes.
• Add the white wine to deglaze the pan and let the wine cook down for a couple of minutes.
• Add the washed fish bones (fish heads) and enough water to cover the bones and heads. This should be somewhere between 7 cups of water.
• Add the black peppercorns, thyme, parsley and bay leaves and bring to a boil.

  As the water is coming to a boil, a white foam will appear at the top of the liquid. Use a large spoon or spatula to remove the foam and as soon as the liquid comes to a boil, reduce heat to a simmer.
• Simmer the stock for 20 to 30 minutes. When done, remove from heat and let the stock cool down for 10 minutes.
• Carefully strain the stock through a fine mesh strainer into another pot or large bowl. Taste and adjust seasoning with salt and pepper to taste.
• If you are not using immediately, let it cool down for another 10 or 15 minutes, transfer to storage containers, cover and chill in the refrigerator.