Ingredients

• 1 large pinch of saffron threads, crumbled
• 1 cup lukewarm water
• 1 2-pound head cauliflower
• 1 tablespoon olive oil
• 1 garlic clove, crushed
• 1 small carrot, cut into 1/4-inch dice (1/3 cup)
• 1/2 cup dry white wine
• 1 cup fat-free reduced-sodium chicken broth
• 1 1/4 teaspoons salt
• 1/2 teaspoon white pepper
• 1 1/2 pounds small to medium mussels (preferably cultivated; 3 dozen), scrubbed and beards removed
• 6 1/4-pound pieces cod or scrod fillet (1 inch thick), skinned and pin bones removed
• 3 scallions, chopped (2/3 cup)
• 2 tablespoons chopped fresh parsley

Instructions

1. Put saffron threads in a small bowl, then stir in lukewarm water and let stand.
2. Trim cauliflower stalk flush with base of crown, discarding stalk, then quarter cauliflower lengthwise. Cut each quarter lengthwise into 1/2-inch-thick slices. Set aside large slices and reserve small pieces without any stem for another use.
3. Swirl oil with garlic in a deep 12-inch heavy skillet to coat, then heat over moderately high heat until oil is just smoking. Discard garlic. Carefully arrange cauliflower slices in 1 layer in skillet and cook until undersides are lightly browned, about 2 minutes. Turn over with tongs and cook until other sides are lightly browned, about 2 minutes.
4. Add carrot and wine and swirl skillet to combine, then boil until liquid is reduced by half, about 30 seconds. Add saffron water, broth, 3/4 teaspoon salt, and 1/4 teaspoon white pepper and simmer, covered, until cauliflower and carrot are crisp-tender, 5 to 8 minutes.
5. While cauliflower simmers, pat fish dry and sprinkle both sides with remaining 1/2 teaspoon salt and 1/4 teaspoon white pepper.
6. Increase heat to moderately high, then add mussels to skillet and steam, covered, until mussels just open wide, checking frequently after 3 to 4 minutes. (Discard any mussels that remain unopened after 8 minutes.) Divide mussels among 6 shallow serving bowls using a slotted spoon.
7. Place cod on top of cauliflower, arranging fillets in 1 layer. Sprinkle with scallions and parsley and steam, covered, over moderately high heat until fish is cooked through, 7 to 10 minutes.
8. Transfer some of cauliflower along with 1 piece of cod to each bowl using slotted spoon. Season broth with salt and white pepper, then ladle broth (with carrots) over each serving.