Seafood Stew With Fennel And Thyme

Ingredients

• 1 1/2 pounds mussels, scrubbed debearded
• 2 1/2 cups chopped onions
• 1 cup dry white wine
• 12 parsley sprigs plus 1/2 cup chopped parsley
• 2 tablespoons (1/4 stick) butter
• 2 cups finely chopped leeks (white and pale green parts only)
• 2 cups diced trimmed fennel bulb
• 4 8-ounce bottles clam juice
• 4 large fresh thyme sprigs
• 2 bay leaves
• 1 3/4 pounds thick halibut fillets, cut into 1 1/2-inch pieces
• 10 ounces sea scallops
• 1 cup crème fraîche
• 2 large egg yolks