SOME WORKS of art stay with you forever. I often think of my mentors’ classic recipes as true works of art. In the mid-1980s, I visited Frédy Girardet in Switzerland, where I savored a fillet of red mullet covered with tiny discs of zucchini to mirror the scales of the fish. Paul Bocuse then made his own version by switching to the more versatile potato “scales,” creating a crispy skin. Once at Le Cirque in New York, I developed my own take with the local black sea bass on a bed of leeks and doused with a rich red wine sauce. It instantly became the most popular dish on the menu and a new classic was born! In the kitchen, the trick is to roast the potatoes to a golden crisp while the fish cooks gently inside the shell. In Cooking with Daniel Boulud, my first cookbook, I introduced the original recipe. After more than twenty years on my menu, it took Eddy Leroux, our chef de cuisine, three years to convince me to take the sea bass en paupiette off, and then only under the condition that we were going to keep the combination of black sea bass, potato, leeks, thyme, and red wine sauce because I couldn’t part with the elements that made that dish a success. In fact, Leroux kept the exact same ingredients but played with them in completely different ways. For example, thyme, which found itself sprinkled on the fish in my original version, now infuses the potatoes, mixed with garlic and onions. The texture of the fish, which cooks in its own steam while encased in the potato scales, is similar in this new version, something we achieve by baking it wrapped in parchment paper.
    Leek Royale
    Pommes Lyonnaise
    Crispy Leeks and Potato Gaufrettes
    Sea Bass
    For the Leek Royale
    1. Preheat the oven to 275°F. Bring a large pot of salted water to a boil and set a bowl of ice water on the side. Add the diced leeks and parsley and boil until very tender, 3 to 4 minutes. Transfer to the ice water to chill; strain and squeeze dry. In a medium saucepan, combine the boiled leeks, parsley, ¾ cup of the heavy cream, and ¾ teaspoon salt and bring to a simmer. Transfer the mixture to a blender and puree until smooth. Pass through a fine-meshed sieve and chill over ice.
    2. In a medium bowl, whisk to combine 1½ cups of the puree with the remaining 1 cup heavy cream, ¾ teaspoon salt, and the eggs; season with pepper. Butter an 8½ × 4½-inch loaf pan and line with parchment paper on the bottom and sides. Pour in the mixture and wrap the pan with plastic wrap; poke 3 small holes in the top of the plastic wrap. Transfer the loaf pan to a roasting pan and fill the roasting pan with enough hot water to reach the level of the leek mixture. Transfer to the oven and bake for 40 minutes, or until set. Cool at room temperature for 10 minutes, remove the pan from the water, then chill in the refrigerator.
    3. Run a knife around the inside edges of the pan and flip the royale onto a cutting board. Peel off the parchment paper and cut into at least twelve 1-inch cubes. Transfer the cubes to a parchment paper–lined baking sheet and reserve, chilled.
    For the Pommes Lyonnaise
    1. In a large saucepan over medium-low heat, melt the butter and stir in the onions with 1 teaspoon salt. Cook, undisturbed, for about 5 minutes, until the onions begin to lightly brown on the bottom. Continue to cook, allowing the onions to lightly brown between stirs, for 15 minutes. If the onions stick to the pan, add a small amount of water. Add half of the thyme and continue the process for another 15 minutes, or until the onions are caramelized and tender. Transfer to a cutting board and finely chop.
    2. Peel the potatoes, and using a Japanese Chiba Peel S turning slicer, cut into long, wide sheets, working quickly to prevent oxidizing. Trim the sheets into two 4-foot lengths and lay them flat. Pat excess water dry with a paper towel. Sprinkle the potato sheets with salt and pepper and spread the surface with a fine layer of garlic paste, followed by the caramelized onion and chopped parsley. Roll the potatoes up from end to end to form tight logs. Tightly roll each log in 2 layers of plastic wrap, then tie off the ends. Using a sharp paring knife, lightly pierce the plastic wrap in several places.
    3. In a medium saucepan, melt the clarified butter with the remaining thyme and heat to 190°F. Submerge the potato logs. Cook until a cake tester easily passes through the potatoes, about 1½ hours. Cool to room temperature, then remove the potatoes from the butter and the plastic. Reserve the butter, chilled. Slice each log into at least three 1-inch discs. Reserve, chilled.
    For the Crispy Leeks and Potato Gaufrettes
    1. Fill one-third of a medium saucepan with canola oil and heat to 325°F. Halve the white leek ends lengthwise and julienne into 1-inch strips. Rinse the leeks with cold water and pat dry with paper towels. Lightly dust with the rice flour. Fry the leeks, in 3 batches, until lightly colored and crispy. Drain onto a paper towel–lined tray and sprinkle with salt.
    2. Slice the potato about -inch thick on a mandoline fitted with a waffle blade, turning the potato a quarter turn after each cut. Using a 1¼-inch ring cutter, punch the slices into at least 6 discs. Increase the oil temperature to 350°F and fry, in batches, until golden brown and crisp. Drain onto a paper towel–lined tray, and sprinkle with salt.
    For the Sea Bass
    1. Cut six 8 × 11-inch sheets of parchment paper and set aside.
    2. Square off the ends and sides of the fillets to form a 7 × 2½-inch rectangle. Lay the fillets skin side up and score a deep cut down the center of the length of the fillet, leaving about ⅓ inch of flesh intact. Fold in the fillets along the score, so the skin is facing outward. Keep chilled.
    3. When ready to serve, season the fish with salt and pepper on all sides. Brush one side of a prepared sheet of parchment paper with butter and wrap, buttered side in, snugly around a piece of fish. Repeat until all the fish is wrapped and place on a baking sheet.
    To Finish
    1. Preheat the oven to 350°F.
    2. In a small saucepan, bring the syrah reduction and heavy cream to a boil. Remove from the heat. Whisk in the butter, a few pieces at a time, just until melted. Season with salt and white pepper and pass through a fine-meshed sieve. Keep warm but do not simmer.
    3. In a medium sauté pan, melt a thin layer of reserved clarified butter and sear the pommes lyonnaise discs on all sides until browned and crispy.
    4. Transfer the fish to the oven and bake for 8 to 10 minutes, until just cooked through. Transfer the leek royale to the oven and bake for 5 minutes. Remove the fish from the parchment paper and sprinkle with fleur de sel and cracked black pepper.
    5. For each serving, place a bass on one side of a warm dinner plate and set 2 discs of pommes lyonnaise and 2 cubes of leek royale on the side. Top the pommes lyonnaise with a gaufrette chip and a leaf of parsley and top each leek royale with crispy leeks. Spoon a line of sauce near the fish.