1⁄8 tsp. Crushed saffron threads (about 12 threads)
9 tbsp. Unsalted butter
1 Leek thinly sliced in rounds
2 cups Cherry tomatoes sliced in half
4 (6-oz.) Atlantic Halibut filets
Kosher salt and freshly ground black pepper, to taste
24 Manilla clams
1 cup white wine
1 tbsp. minced fresh flat-leaf parsley leaves
Heat oven to 225. Combine saffron and 1 1⁄2 cups warm water in a small bowl; set aside. Grease a 10″ straight-sided pan with 1 tbsp. butter. Arrange leeks and tomatoes in the pan. Season halibut with salt and pepper; arrange in skillet. Scatter clams around filets; pour the reserved saffron liquid and the wine around the halibut. Cover and bring to a boil, reduce heat to medium-low, and cook until the clams open, about 3 minutes. Remove pan from heat; set aside, covered, to let steam until halibut is cooked through, about 5 more minutes.
Using a metal spatula, transfer fish and clams to a baking sheet, and transfer baking sheet to oven to keep warm. Gently strain the tomatoes and leeks, reserving the liquid back in the pan.Return pan high heat and bring to a boil. Whisk in remaining butter 1 tbsp. at a time. Remove pan from heat and stir in parsley. Season broth with salt. Divide fish, clams, tomatoes and leeks between 4 bowls and spoon broth over top.