Ingredients

• 2 cups white wine
• 2 celery stalks, cut into 1-inch lengths
• 2 cups celery leaves
• 2 carrots, peeled and cut into 1-inch lengths
• 1 teaspoon black peppercorns
• 4 to 5 bay leaves, preferably fresh
• 1 (4 pound) salmon fillet, boned and skinned
• 1 (4-ounce) package Japanese cellophane noodles
• 10 tablespoons unsalted butter, plus 8 tablespoons, melted, for serving, and more for buttering pan
• 1 tablespoon canola oil
• 4 leeks, cleaned and thinly sliced, white parts only
• 1/2 cup chopped fresh dill
• Coarse salt and freshly ground pepper
• 12 ounces mushrooms, sliced, such as shiitake or white button
• 2 hard-boiled eggs, coarsely chopped
• Cayenne pepper, to taste
• 1/4 cup freshly squeezed lemon juice, plus 2 tablespoons, for serving
• 2 pounds Puff Pastry, chilled, recipe follows
• 2 large egg yolks
• 2 tablespoons heavy cream
• 1 pound all-purpose flour, accurately weighed
• 1 pound (4 sticks) cold unsalted butter, cut into small pieces
• 1 teaspoon salt
• 1 cup heavy cream (or 1/2 cup heavy cream mixed with 1/2 cup ice water)

Instructions

1. In a large fish poacher over medium heat, combine wine, celery, celery leaves, carrots, peppercorns, and bay leaves. Place salmon over vegetables, and add enough water to cover. Bring to a simmer, and cook until just done (still pink inside), about 15 minutes. Remove salmon from poacher; allow to cool. Using your hands, flake salmon into small pieces and place into a large bowl. Place cellophane noodles in a medium bowl. Pour over enough hot water to cover. Let sit until soft, about 7 minutes. Heat 4 tablespoons butter and canola oil in a large saute pan over medium heat. Add leeks, and saute until soft, about 4 minutes. Transfer to bowl with salmon. Add dill, salt, and pepper. Heat remaining 6 tablespoons butter in same saute pan over medium heat. Add mushrooms, and saute over high heat until dark brown, 2 to 3 minutes. Drain noodles, chop finely, and add to the salmon mixture. Stir in hard-boiled eggs, salt, pepper, cayenne, and lemon juice. Mix well to combine, and cover with plastic wrap. Refrigerate until ready to use. Heat oven to 400 degrees F. Butter a baking sheet. Set aside. To assemble the coulibiac, roll out the puff pastry on a lightly floured surface to 1/8-inch thick, 20 by 24-inches. Using a sharp knife, divide pastry into a 9 by 24-inch rectangle and an 11 by 24-inch rectangle. Place the small rectangle on the prepared baking sheet. Mound salmon filling on the rectangle, leaving a 3/4-inch border. Brush the pastry border with ice water, and cover with larger top pastry rectangle. Trim corners, fold bottom pastry over, and press tightly to seal. Gather the scraps. Roll again, and cut into decorative shapes. Brush with ice water, and attach to coulibiac as desired. In a small bowl, whisk together egg yolks and cream. Brush the surface of the coulibiac with egg-yolk mixture. (The coulibiac can be refrigerated at this point up to 3 or 4 hours.) Using a small paring knife, cut a circle, about 1/2-inch in diameter, out of the top center of the coulibiac to allow steam to escape. Bake until puffed and golden brown, about 30 minutes. Let cool slightly before slicing into serving pieces. Meanwhile, in a small saucepan over low heat, melt 8 tablespoons butter. Remove from heat, and add 2 tablespoons lemon juice. Spoon over sliced coulibiac as desired.;
2. Step 1. In the bowl of a food processor or using the flat paddle of an electric mixer, mix 1/2 cup flour with butter until very smooth. Shape the mixture into a flat square 1 inch thick, wrap well in plastic, and chill for at least 30 minutes. Step 2. Combine salt with the remaining flour in a large mixing bowl, and add cream (or cream and water). Mix the dough well by hand or with an electric mixer; the dough will not be completely smooth but it should not be sticky. Shape it into a flat square 1 1/2 inches thick, wrap in plastic, and chill, at least 30 minutes. Step 3. Remove the flour dough from the refrigerator. On a lightly floured board, roll the dough into a rectangle twice as long as the butter dough. Place the butter dough in the center, fold up the ends to completely encase the butter dough, and seal the edges by pinching them together. Wrap well in plastic, and chill for at least 30 minutes, so that the dough achieves the same temperature throughout. Step 4. Remove the dough from the refrigerator and, on a lightly floured board, roll it out into a large rectangle approximately 1/2 inch thick. Fold the dough into thirds, aligning the edges carefully and brushing off any excess flour. The object is to ensure that the butter is distributed evenly throughout, so that the pastry will puff evenly when baked. Wrap the dough, and chill it for at least 30 minutes. This completes 1 turn. Step 4 should be repeated 5 more times; classic puff pastry gets 6 turns, creating hundreds of layers of butter between layers of the flour dough (729 to be exact). Use as little flour as possible when rolling out the dough, and always brush of any excess. Remember to let the dough rest for at least 30 minutes in the refrigerator between turns, or 15 minutes in the freezer. This chilling makes the rolling out much easier, and it keeps the layers of butter of equal thickness. By the 6th and final turn, the dough should be very smooth, with no lumps of butter visible. Wrap the pastry in plastic wrap, and refrigerate until ready to use (up to 2 days), or freeze for future use.
3. Yield: approximately 2 pounds