by Giulia Berti
13 Dec 2023

Vegetarian Mushroom Wellington

Looking for a show-stopping vegetarian dish that will impress your guests? Look no further and try this Vegetarian Mushroom Wellington!
This savory delight features a medley of flavorful mushrooms, caramelized onions, and toasted walnuts, all encased in a golden, flaky puff pastry. Organic king oyster mushrooms are the star of this Christmas dish, perfectly cooked to add texture and rich flavor.

Ingredients

4 large organic mushrooms (each about 3 inches wide, 8 to 10 ounces total)
½ cup plus 5 tablespoons olive oil
Kosher salt and black pepper
2 pounds mixed mushrooms (such as shiitake, oyster, and cremini)
Ice, for cooling
4 shallots, finely chopped (about 1 packed cup)
6 garlic cloves, finely chopped
2 tablespoons finely chopped fresh rosemary
⅓ cup port, or 1 to 2 tablespoons good-quality aged balsamic vinegar
2 tablespoons soy sauce
1 tablespoon fresh thyme leaves
1 cup finely chopped toasted walnuts (about 4 ounces)
3 tablespoons unsalted butter
2 small yellow onions, cut into ¼-inch rounds
¾ teaspoon light or dark brown sugar
1¼ teaspoons kosher salt
¾ teaspoon black pepper
1 cup apple cider or apple juice
1 tablespoon good-quality aged balsamic vinegar (optional)
All-purpose flour, for dusting
1 (14-ounce) package puff pastry
1 large egg, beaten
Port Reduction (optional)

Instructions
Step 1:

Wipe the mushrooms clean using moist paper towels.
Remove the stems and slice off the excess rim that curls over the gills to create a flat surface.
Brush the caps on both sides with 3 tablespoons of olive oil and season with salt and pepper.
Heat 2 tablespoons of olive oil in a large nonstick skillet over medium-high heat.
Cook the mushrooms, gill-side down, until caramelized for about 5 minutes, then flip and cook for another 5 minutes.
Transfer the mushrooms to a wire rack, gill-side down, to cool.

Step 2:

Separate and reserve any mushroom stems.
Roughly chop about two-thirds of the mixed mushrooms.
Transfer the roughly chopped mushrooms to a food processor and pulse into small, ¼- to ½-inch pieces.
Finely chop the remaining mixed mushrooms and stems into ¼-inch pieces.
Combine all the chopped mushrooms in a large bowl.

Step 3:

Prepare an ice bath in a large bowl.
Wipe out the skillet and warm ¼ cup of olive oil over medium-high heat.
Add half of the mushrooms, shallots, garlic, and rosemary to the skillet and season with salt and pepper.
Cook, stirring occasionally, until caramelized and tender for about 10 minutes.
Transfer to a medium bowl.
Repeat the process with the remaining ¼ cup of oil and the remaining mushrooms, shallots, garlic, and rosemary.
Return the first batch to the skillet.
Add port, soy sauce, and thyme leaves, and cook until the liquid evaporates for 3 to 4 minutes.
Transfer the mixture to the medium bowl and stir in the chopped walnuts.
Set the bowl over the ice bath to cool for at least 20 minutes, stirring occasionally.

Step 4:

Wipe out the skillet and melt the butter over medium heat.
Add the onions, sugar, salt, and pepper, and cook for 5 minutes, stirring occasionally.
Add the cider and cook until the liquid evaporates and the onions are caramelized for about 15 minutes.
Stir in the balsamic vinegar (if using) and let cool.

Step 5:

Preheat the oven to 400 degrees Fahrenheit.
Place a large piece of parchment paper on your work surface and lightly dust it with flour.
Unfold the thawed puff pastry on the parchment and roll it out into a 13-by-16-inch rectangle using a lightly floured rolling pin.
Transfer the parchment paper and puff pastry to a large sheet pan.
Arrange half of the cooked mushroom mixture in a 4-by-10-inch strip in the center of the puff pastry, leaving a 1½-inch border at the ends.
Arrange the caramelized onions in a 3-inch-wide strip on top.
Lay the mushrooms on top of the onions in a single line, stem-side down.
Spoon the remaining mushroom mixture on top, covering the mushrooms, and shape it like a freeform meatloaf.

Step 6:

Lift one side of the puff pastry over the filling to almost completely cover it.
Brush the surface of the puff pastry covering the mushrooms with the beaten egg.
Lift the remaining puff pastry flap over the egg-washed puff pastry, gently pressing the top layer onto the lower layer to seal.
Brush the insides of the short ends of the puff pastry and press to seal, tucking both sides underneath.
Trim any excess parchment paper.
You can refrigerate the pastry at this point(Continuation of the Vegetarian Mushroom Wellington recipe):

Step 7:

Brush the exposed puff pastry on top with the remaining beaten egg.
Decorate the top of the puff pastry as desired, such as creating a cross-hatch pattern or small decorative vents.
Bake the Wellington until the puff pastry is deep golden and flaky for about 45 to 50 minutes.
Let it cool slightly on the baking sheet for about 10 minutes.

Step 8:

While the Wellington bakes, prepare the optional port reduction.
In a medium saucepan, heat the oil over medium heat.
Add the shallot, garlic, and peppercorns, and cook for 3 minutes.
Add the port, stock, and thyme, and cook until the sauce is glossy for about 25 to 30 minutes.
Strain the sauce, then reheat over medium heat.
Whisk in the butter, and season with salt and pepper.

Step 9:

To serve the mushroom Wellington, cut it crosswise into 8 even slices.
Serve each piece presentation-side up, showcasing the halved mushroom in the center.
Optionally, drizzle the port reduction on top.