halibut acorn truffle celery

Ingredients

• 1 .6 kilograms | 5 ½ cups kosher salt
• 90 grams | 2 cups celery leaves
• 15 grams | ⅓ cup thyme leaves
• 450 grams | 1 pound halibut fillet, skin removed

• 2 kilograms | about 8 cups heavy cream
• 300 grams | 10.5 ounces oak chips
• 700 grams | about 1.5 pounds celery root, peeled and finely diced
• kosher salt

• 350 grams | 12 ounces peeled and diced celery root
• 40 grams | 3 tablespoons extra virgin olive oil
• kosher salt
• 100 grams | ⅓ cup dark chicken jus
• 25 grams | 3 tablespoons black truffle, in brunoise

1. FOR THE HALIBUT PREPARATION: Combine 450 grams (1 ½ cups) of the salt and the celery and thyme leaves in a food processor and mix for 1 minute, until the leaves are pulverized and fully mixed with the salt. Transfer to a bowl and mix in the remaining salt. Bury the halibut fillet in the seasoned salt and refrigerate for 10 minutes. Rinse the fillet in a bowl of ice water and pat dry on paper towels. Cut the fillet into rectangular portions about 2 inches (5 centimeters) wide by 5 inches (13 centimeters) long. Scale each portion to about 100 grams (3.5 ounces). Store in an airtight container in the refrigerator.
2. FOR THE CELERY ROOT PUREE: Combine the cream and oak chips in a stockpot. Bring to a boil over high heat, turn down the heat to a simmer, and cook for 20 minutes, until the cream is infused with the flavor of oak. Remove from the heat and strain the cream, discarding the chips. Return the cream to the pot, add the celery root, and bring to a boil. Cook for about 15 minutes, until the celery root is soft. Meanwhile, prepare an ice bath. When the celery root is ready, drain and discard the cream. Place the celery root in a blender and mix on high speed for about 3 minutes, until a very smooth puree forms. Strain through a chinois into a bowl, then nest the bowl in the ice bath to cool the puree. Season with kosher salt, transfer to a squeeze bottle, and refrigerate until needed.
3. FOR THE BRAISED CELERY ROOT: Season the celery root with the olive oil and salt. Transfer the celery root to a vacuum bag, seal on high, and cook in a steam oven set at 200°F (95°C) for 25 to 30 minutes, until very tender. Remove the celery root from the bag and finely mince it. Transfer the celery root to a saucepan and warm gently over low heat. Add the chicken jus and increase the heat to a boil. Reduce the residual liquid until the mixture is fairly dry. Add the truffle and season with kosher salt. Hold in an airtight container at 120°F to 130°F (49°C to 54°C) for up to 1 hour.
4. FOR THE ACORN GRAVY: Combine the water and kombu in a small saucepan over low heat and simmer for 15 minutes. Meanwhile, melt the butter in a small sauté pan over low heat. Add the acorn flour and mix together with a spatula. Once the mixture has thickened, cook, stirring, for 4 minutes to toast the flour. Transfer to a metal container and let cool in the refrigerator. When the kombu stock is ready, strain it through a fine-mesh strainer into a clean saucepan.
5. Once the acorn roux has cooled completely and stiffened, break it up into small pieces and whisk the pieces into the kombu stock. Place over medium heat and bring to a boil, whisking constantly. When the gravy has thickened, season with kosher salt and strain through a chinois. Hold in an airtight container at 120°F to 130°F (49°C to 54°C) for up to 1 hour.
6. FOR THE TRUFFLE JUS: Heat the chicken jus in a small saucepan over low heat to about 180°F (82°C). Add the truffle and season with sherry vinegar and salt. Hold in an airtight container at 120°F to 130°F (49°C to 54°C) for up to 1 hour.
7. FOR THE ROASTED CUTTING CELERY: Pour the olive oil into a cast-iron pan over high heat. Add the celery pieces and sauté until the celery begins to brown slightly. Remove from the pan and season with kosher salt. Pat dry on paper towels.
8. FOR THE PICKLED TINY CELERY: Prepare an ice bath. Combine the vinegar, water, and sugar in a small saucepan and bring to a simmer over low heat, stirring until the sugar dissolves. Remove from the heat and nest the pan in the ice bath to cool the pickling liquid. Use the cooled liquid to dress the tiny celery. Season with Maldon salt.