Beef Wellington is a classic yet complicated dish, but in our vegetarian version – which replaces the beef with Ontario mushrooms – we’ve simplified the process and created a dish that’s worthy of your plant-loving holiday guests. Feel free to prep the mushroom mixtures (both the roasted portabellas and the sautéed creminis) up to three days in advance to make this easier to put together. Also, if it suits your taste scatter crumbled goat cheese over the mushrooms before rolling it up in the puff pastry.
- 1 sheet frozen puff pastry
- 2 portobello mushrooms (about 6 ounces total)
- 3 tablespoons olive oil, divided
- 1 ½ teaspoons kosher salt, divided
- 1 teaspoon freshly ground black pepper, divided
- 2 (10-ounce) packages Ontario cremini or white mushrooms
- 2 tablespoons butter
- 3 garlic cloves, minced
- 1 small Ontario onion, finely diced
- 8 ounces fresh oyster or shiitake mushrooms, roughly chopped
- 1 tablespoon fresh thyme leaves
- 1 tablespoon fresh rosemary leaves
- 2 cups packed baby spinach
- 1 cup cooked couscous
- 2 tablespoons Dijon mustard
- 1 large egg
- Thaw the puff pastry according to package directions and keep refrigerated until ready to use.
- Preheat the oven to 425°F and line a baking sheet with parchment paper.
- Trim the stems from the portobello mushrooms. Cut into 1-inch thick strips and place on the baking sheet. Drizzle with 1 tablespoon olive oil, season with ½ teaspoon kosher salt and ½ teaspoon black pepper and toss to combine. Spread into a single layer and roast, flipping the mushrooms halfway through, until shriveled and start to leak moisture, 12 to 15 minutes total.
- Transfer the portobellos to a large plate and set aside to cool. Set aside the parchment and baking sheet. Reduce the oven heat to 400°F.
- Place the cremini mushrooms in a food processor fitted with the blade attachment. Pulse until coarsely chopped, 15 to 25 pulses.
- Heat the remaining 2 tablespoons olive oil and 2 tablespoons butter in a large skillet set over medium-high heat. Add the garlic and onion and cook until just softened, 2 to 3 minutes. Add the cremini and oyster mushrooms and cook until tender, golden and the moisture evaporated, 6 to 7 minutes more. You’re looking for there to be no liquid in the pan.
- Stir in the thyme, rosemary, spinach, couscous, remaining salt and remaining black pepper. Cook until the spinach is wilted, 1 to 2 minutes. Remove from the heat and stir in the Dijon mustard. Transfer to the reserved baking sheet, spread into an even layer, and cool completely.
- Line a second baking sheet with parchment paper. Unfold the puff pastry on the parchment with a short side closest to you. Spoon half of the mushroom mixture down the center of the puff pastry in an even layer, leaving a 2-inch border around the sides. Place the portobello mushroom pieces on top of the mixture in an even layer, and then spoon the remaining mushroom mixture on top, pressing gently down to pack the mixture around the portobellos.
- Carefully fold both long sides of the puff pastry to meet over the center and pinch the edges together seal. Fold the ends over and pinch to seal so that the pastry completely wraps over the filling. Using the parchment paper, gently roll the Wellington over so that the seam is on the bottom.
- Using a paring knife, gently score the top of the puff pastry with a crosshatch pattern without cutting all the way through the pastry. Beat the egg and 1 tablespoon water in a small bowl until combined, then brush the top and sides of the Wellington with the egg wash.
- Bake until golden brown and cooked through, 30 to 35 minutes. Let rest for at least 20 minutes before slicing and serving.