To make the Mushroom Stock: Grind mushrooms through a meat grinder fitted with the largest die. Place mushrooms, 600 g. (21.1 oz.) water, and oil into a vacuum bag. Vacuum seal on liquid setting. Cook in a Rational combi oven at 145F (63C) on steam mode for 12 hours. Strain mushroom mixture through towel, pressing to ensure all liquid is released. Cool liquid and skim oil. Transfer the cooled liquid back to a vacuum bag and seal. Place in freezer and allow to freeze completely.

Remove bag from freezer and break into pieces by using either a Stainless Clad Butter Warmer or a Rolling Pin. Transfer crushed ice to a chinois lined with linen. Allow to drip at room temp until ice in chinois is completely colorless. Reserve liquid and cool.

To make the Vegetable Jus: Shave all vegetables thinly on a mandoline. Combine vegetables in a large bowl. Add tomato paste and oil; mix thoroughly. Transfer to a Stainless Clad Roasting Pan or hotel pan and spread into an even layer. Use multiple pans if needed. Roast at 350F for 45 minutes, stirring the vegetables halfway through. There should be heavy caramelization but not burning.

Once even caramelization is achieved, transfer to a large Stainless Clad Stock Pot. Rinse and scrape the pans with water to release the fond; add to Pot. Add water and kombu and bring to a simmer. Place a cartouche (paper lid made of parchment with a hole in the center) on top and let cook for 40 minutes. Strain immediately. Transfer to a clean Pot and allow to reduce slightly until desired flavor. Weigh the liquid and thicken with xanthan gum at 0.1%. Pass through a chinois. To serve, heat jus, and break with olive oil.

To make the Braised Pearl Onions: In a medium Stainless Clad Saucepan or Saucier, bring the Madeira up to a boil. Flambé with a torch. Remove from heat when flame stops. In a medium Stainless Clad Saucepan or Saucier, combine Madeira, vinegar, sugar, tamari, and Worcestershire. Bring up enough to dissolve the sugar. In a vacuum bag, combine 50 g. cooking liquid with enough onions to form an even layer in the bag. Season with salt and a knob of butter. Seal, then steam in a Rational combi oven at 185F (85C) for 15 minutes.

Remove from oven and chill in an ice bath. Open bag and reserve liquid. Cut the onions in half (length-wise) and sear until browned in a large Stainless Clad or Non Stick Frying Pan. Cool and keep in cooking liquid.

To make the Truffled Cippolini Onion Mix: Heat a Stainless Clad Rondeau over medium. Add butter and onions. Season with salt, cover with a cartouche, and cook until tender (about 15 minutes). Drain the fat from the onions with a chinois. Transfer back to the rondeau, add the truffle haché, and cook for 5 minutes. Deglaze with Madeira and reduce to sec (reduced until almost dry). Add the cream and cook until nappe (thick enough to coat the back of a spoon). Transfer to a Sheet Pan and cool.

To make the Pan-Roasted Mushrooms: In a large Stainless Clad Frying Pan over high heat, add enough canola oil to coat the pan. When smoking, add mushrooms. Season with salt and stir frequently to achieve good color on all sides. Add a few knobs of butter, garlic cloves, and thyme. Turn the heat down slightly and stir frequently. Let cook 5 minutes. Remove from heat and drain mushrooms on a paper lined Sheet Pan. Discard garlic and thyme, cool, and reserve.

In frying pan over medium-high heat, add a splash of canola oil and the sautéed mushrooms. Once warm, add shallot and stir constantly until tender. Deglaze with Sherry and bring to sec. Add a splash of Mushroom Stock (see above) and a knob of butter. Let reduce until a tight glaze is formed. Season with salt and pepper to taste.

To assemble and serve 4 tarts: Lay first sheet of brick dough down on work surface and lightly brush evenly with tempered butter. Lightly season with garlic and porcini powder. Place the second sheet on top and repeat the process. Place the third sheet on top and press down to ensure the layers are sealed. Repeat with remaining layers to form 4 tarts. To shape, place desired size of ring mold over top. Using a pairing knife, cut around the edge of the mold. Store raw tarts in the cooler between layers of parchment.

When ready to cook, transfer tarts to a Sheet Pan and place a ring mold on top of the tart that is a smaller size leaving about 1 cm. on all edges. Place desired amount of Truffled Cippolini Onion Mix into the ring. While holding ring in place, evenly distribute onion mixture with the back of a spoon. Bake in an oven at 392F (200C) for 4 minutes. Remove from oven and place into a large Non Stick Frying Pan.

Meanwhile, combine Braised Pearl Onions and Pan-Roasted Mushrooms in another large Pan and gently reheat over medium heat. Set Pan with tart over low heat. Top with onion and mushroom mixture and lightly crisp the bottom. Transfer to a Butcher Block and cut into 4 sections. Transfer to plate and top with herb salad, julienned truffle, Parmesan curls, Espelette pepper, and a drizzle of warmed Vegetable Jus cut with olive oil.