Heat the oil in a large
saucepan over medium-high heat. Add the
fennel, onions and garlic and cook, stirring frequently to prevent sticking, for about 10 minutes. Then add the tomatoes, peppers and thyme. Continue to cook and stir for 8 minutes. Add the white
wine and cook until it has reduced by half. Then add the fish
stock. Increase the heat and bring to a boil. Add the fish and decrease the heat to a
simmer. Cook for 5 minutes. Add the basil and Espelette, then turn off the heat and let cool slightly. Place the sauce into a blender and blend until smooth. Season with salt and pepper.
Cook's Note: When blending hot liquids, remove liquid from the heat and allow to cool for at least 5 minutes. Transfer liquid to a blender or
food processor and fill it no more than halfway. If using a
blender, release one corner of the lid. This prevents the vacuum effect that creates heat explosions. Place a towel over the top of the machine,
pulse a few times then process on high speed until smooth.