In a 5- to 6-quart pan, combine oil, celery, onion, fennel, and bell pepper. Stir often over medium-high heat until onion is limp, 8 to 10 minutes. Add curry powder and stir until mixture is quite fragrant, 2 to 3 minutes.
Add brandy, Pernod, broth, clam juice, wine, tomato paste, and saffron. Bring to a boil. Cover and simmer until vegetables are very tender when pierced, about 15 minutes. Whirl mixture, a portion at a time, in a blender until smooth. If desired, pour broth through a fine strainer into a bowl, rubbing with a spatula; discard any residue. If needed, add water to make 6 1/2 cups. Add salt and pepper to taste.
Use in bouillabaisse or ladle hot broth into bowls.