Roast the bell peppers directly over a gas flame or under the broiler, turning, until charred. Transfer to a paper bag and let steam for 15 minutes. Peel the peppers, discarding the cores, ribs and seeds; coarsely chop the peppers.
Heat the olive oil in a large non-reactive saucepan. Add the carrots, fennel, leeks, onion and garlic and cook over moderate heat, stirring occasionally, until the vegetables are softened but not browned, about 8 minutes. Add the peppers, white wine, Pernod, thyme, fennel seeds and 4 cups of water and season with salt and pepper. Reduce the heat to low, cover and simmer until the vegetables are soft, about 40 minutes.
Transfer the soup to a blender and blend until smooth. Season with salt and pepper. Stir in the basil and parsley and thin with a little water if the soup is thick. Serve the soup warm, at room temperature or chilled, garnished with the leafy fennel tops
The soup can be refrigerated overnight.
Cooking Club Tip: Take care when pureeing hot soup: transfer ingredients to the blender in batches, filling it no more than halfway. Alternatively, a handheld immersion blender will make quick work of the sautéed vegetables if they are transferred to a deep pot or bowl.