Ingredients

Equipment Needed

• •Large heavy skillet (12-inch preferred)
• •Rolling pin
• •Parchment-lined baking sheet
• •Sharp serrated knife for slicing

Instructions

1. 1

   Prepare the mushrooms

   Brush off any dirt from your mushrooms with a damp cloth. Do not soak them. Mushrooms are porous and will drink up water, which steams out during cooking and prevents browning. Remove tough stems from shiitakes, trim the ends from creminis, and scrape the gills from portobellos if you prefer a cleaner look. Chop everything into rough, uneven pieces about the size of your thumbnail.

   Variety matters here. Each mushroom brings something different: creminis for meatiness, shiitakes for depth, oysters for delicacy. Use what looks alive at your market.
2. 2

   Cook mushrooms in batches

   Heat a large, heavy skillet over medium-high heat. Add two tablespoons of olive oil. When the oil shimmers, add half the mushrooms in a single layer. Leave them alone. Do not stir. After three to four minutes, the bottoms will be deeply golden and the edges will look lacquered. Stir once, then cook another two minutes until browned throughout. Season with salt and pepper, then transfer to a bowl. Repeat with remaining oil and mushrooms.

   Crowding the pan causes mushrooms to steam rather than sear. They release water, turn gray, and taste of nothing. Work in batches. This step is where flavor is built.
3. 3

   Build the aromatics

   Lower the heat to medium. Add a splash more oil if needed. Cook the shallots until softened and translucent, about four minutes. Add the garlic, thyme, and rosemary. Stir constantly for one minute until fragrant. The kitchen should smell like someone who knows what they are doing.

4. 4

   Deglaze and reduce

   Pour in the white wine. It will sizzle and steam. Scrape up any browned bits clinging to the pan because that is where the flavor lives. Let the wine reduce until nearly evaporated, about two minutes. Add the tamari and mustard, stirring to combine.

5. 5

   Combine and cook down

   Return all the mushrooms to the pan along with any collected juices. Add the spinach in handfuls, letting each batch wilt before adding more. The leaves will cook down to almost nothing. Stir in the walnuts. Cook until any remaining liquid evaporates and the mixture is thick and cohesive, about five minutes. Taste and adjust seasoning. The filling should be deeply savory. Transfer to a baking sheet, spread thin, and cool completely.

   The filling must be cold before wrapping. Warm filling melts the pastry layers and produces a soggy bottom. Patience here pays off at the table.
6. 6

   Roll and shape the pastry

   On a lightly floured surface, roll the puff pastry into a rectangle about 12 by 14 inches. It should be thin enough to see the shadow of your hand through it but sturdy enough to handle. Mound the cooled mushroom filling in a log shape down the center, leaving three inches of pastry bare on each side and two inches at both ends.

7. 7

   Seal the Wellington

   Brush the exposed pastry edges with plant milk. Fold the short ends up and over the filling, then roll one long side over to meet the other, pressing firmly to seal. You want a snug package with no gaps where steam can escape. Place seam-side down on a parchment-lined baking sheet. Refrigerate for at least thirty minutes.

   This rest firms the butter layers in the pastry, ensuring dramatic puff and flake. Skip it and the pastry slumps.
8. 8

   Score and glaze

   Preheat the oven to 400F. Remove the Wellington from the refrigerator. Brush the entire surface with plant milk. Using a sharp knife, score the top with diagonal lines about half an inch apart, cutting just through the surface layer. Sprinkle with flaky salt.

9. 9

   Bake until golden

   Bake for 40 to 45 minutes until the pastry is deeply golden and puffed, with visible layers along the sides. The scoring lines should have opened into pronounced ridges. If the top browns too quickly, tent loosely with foil for the final ten minutes.

10. 10

    Rest and slice

    Let the Wellington rest on the baking sheet for ten minutes before slicing. This allows the filling to set and makes cleaner cuts. Use a sharp serrated knife. Slice into rounds about one and a half inches thick, revealing the dark earthy filling encased in golden flaky pastry. Serve on warmed plates.

Chef Tips

• •Visit your farmers market for mushrooms. The growers there often have varieties you will never find in supermarkets: maitake, lion's mane, black trumpet. Each one brings something different to the filling.
• •Do not skip the wine. It deglazes the pan and adds acidity that brightens the earthiness of the mushrooms. If you prefer not to cook with alcohol, use vegetable stock with a splash of lemon juice.
• •This Wellington shines in late autumn and winter when mushrooms are at their peak. If you make it in summer, seek out cultivated varieties from a good source rather than settling for tired supermarket creminis.
• •The filling can be made entirely ahead, up to two days before assembly. In fact, it improves with time as the flavors marry. Just be sure it is completely cold before wrapping.

Advance Preparation

• •The mushroom filling can be made up to two days ahead and refrigerated. The flavors deepen overnight.
• •The assembled Wellington can be refrigerated, unbaked, for up to 24 hours. Add five minutes to baking time if going directly from refrigerator to oven.
• •Baked Wellington is best served the day it is made. Leftover slices can be reheated in a 375F oven for 10 minutes to re-crisp the pastry.

Frequently Asked Questions

Nutrition Information

1 serving (about 200g)