Ingredients

• 1/4 cup mayonnaise
• 1 garlic clove, minced
• Pinch of cayenne pepper
• Mediterranean bouquetgarni (1/3 cup fennel fronds; 4 thyme sprigs; two 5-inch-long strips orange peel)
• 3 tablespoons olive oil
• 1 3/4 cups chopped fresh fennel bulb (from 1 large)
• 1 cup thinly sliced leek (white and pale green parts only)
• 1/2 cup dry white wine
• 1/4 teaspoon saffron threads
• 3 cups low-salt chicken broth
• 1 1/2 pounds halibut fillets, cut into 1-inch pieces
• 4 1-inch-thick baguette slices

Instructions

1. Mix mayonnaise, garlic, and cayenne in small bowl. Cover and chill rouille. (Can be prepared 1 day ahead.)
2. Place fennel fronds, thyme sprigs, and orange peel on large square of 2 layers of moistened cheesecloth. Gather cheesecloth and tie securely. Heat 2 tablespoons oil in heavy large pot over medium-high heat. Add fennel bulb and leek and sauté until soft, about 8 minutes. Add wine and saffron; bring to boil. Add broth and bouquet garni; return to boil. Cover, reduce heat to medium-low, and simmer 45 minutes. Add fish and simmer until opaque in center, about 5 minutes.
3. Meanwhile, preheat oven to 375°F. Brush baguette slices with remaining 1 tablespoon oil. Arrange on baking sheet. Bake until golden brown, about 8 minutes. Spread rouille on toasts. Ladle stew into wide soup bowls, top with toasts, and serve.