For the stock
Heat the oil in a large rondeau and sweat the vegetables until soft. Add the fish bones and also sweat for until they are opaque, 10 to 12 minutes. Pour the wine into the pot and let it reduce by ½. Add the water and bring to a simmer at 82⁰C to 85⁰C. Skim the scum from the surface and add the thyme, bay leaves, parsley stems and peppercorns. Simmer uncovered for 35 to 40 minutes, skimming the surface as necessary. Strain the fumet. It may be used now (degrease by skimming, if necessary) or rapidly cooled and stored for later use.