1. Combine tomatoes, broth, chopped fennel bulb, garlic, oil, saffron, if desired, basil, and red pepper flakes in slow cooker. Cover; cook on low 4 to 5 hours or on high 2 1/2 to 3 hours, or until fennel is tender.
2. Stir in halibut or cod and shrimp. Cover; cook 15 to 30 minutes, or until shrimp is pink and opaque and fish begins to flake when tested with a fork. Ladle soup into shallow bowls. Garnish with chopped fennel fronds.
Dining and Cooking