Go Back
Four individual mushroom wellingtons with spinach and walnuts on a squares of parchment paper.
Print Recipe
4.67 / 3 votes

Mushroom Wellingtons with Spinach

This mushroom wellington with spinach is essentially a meaty portobello mushroom and spinach-walnut filling in flaky puff pastry. A spectacular vegan and vegetarian option, whether for Thanksgiving or any time of year. And you can easily assemble it ahead of time and bake it at the last moment.
Prep Time30 minutes
Cook Time50 minutes
Total Time1 hour 20 minutes
Course: Mains
Cuisine: American
Servings: 4 servings
Calories: 1076

Ingredients

For the wellingtons

  • 4 Portobello mushrooms
  • Olive oil
  • 1 large red onion, finely chopped
  • 2 garlic cloves, finely chopped
  • Kosher salt
  • 9 ounces cremini or button mushrooms (about 12 mushrooms)
  • 1 teaspoon dried rosemary
  • 1 teaspoon dried thyme
  • 3/4 cup chopped walnuts
  • 2 tablespoons white miso paste
  • 3 1/2 ounces spinach, coarsely chopped
  • Two sheets of store-bought or homemade puff pastry, thawed if frozen (if making this vegan, be certain to use pastry that doesn't contain butter)
  • Splash of almond or oat milk
  • Freshly ground black pepper

For the vegan horseradish sauce

  • 1 cup cashew nuts
  • 2 garlic cloves, roasted
  • 1 teaspoon Dijon mustard
  • 1 tablespoon apple cider vinegar
  • 3/4 cup almond milk
  • 3 tablespoons fresh horseradish, grated, or more to taste
  • Salt and freshly ground black pepper
US - Metric

Instructions

Make the mushroom wellingtons

  • Preheat the oven to 350°F (177°C).
  • Remove the stalks from the mushrooms and reserve. Place the whole caps, cup-side down, on a rimmed baking sheet. Drizzle the mushrooms with olive oil, add a pinch of salt and pepper, and roast for 10 minutes.
  • In a large saucepan over medium heat, warm 1 to 2 tablespoons oil. Add the onion, garlic, and a pinch of salt. Stir together and cook until softened, 5 to 10 minutes.
  • Finely chop the cremini mushrooms and the Portobello stalks into pieces no larger than 1/2 inch (12 mm).
  • Add the mushrooms to the pan with the onion and cook until softened and all the water has evaporated, 5 to 10 minutes more.
  • Stir in the rosemary, thyme, walnuts, and miso and cook for 5 minutes. Add the spinach and cook, stirring, until wilted. Spoon into a bowl and let cool completely. (You can prepare, cover, and refrigerate this for up to 1 day before using.)
  • Roll out 1 of the sheets of puff pastry, including the paper, onto a rimmed baking sheet, using the paper to line the pan, and cut it into 4 squares, approximately 6 by 6 inches (15 by 15 cm). Separate the pieces.
  • Spoon equal amounts of the mushroom mixture onto each piece of pastry before topping each one with a whole Portobello mushroom (leave about 1/2 inch [12 mm] along the sides of each to reveal the pastry). Brush the edges of the pastry with a little almond milk.

    ☞ TESTER TIP: If you prefer, you can place the Portobello cup side up and divvy the mushroom filling between the cups.

  • Roll out the other sheet of puff pastry on a board and cut into 4 squares to the same size as the first pieces. Place one over the top of each wellington, gently squashing down the filling if needed. Press around the edges of the pastry, using one finger and thumb to create a crimped effect and to seal the wellingtons. You can then trim the corners of the squares to form neat circles around the mushrooms.
  • Cut thin slits in the top of each wellington and brush with almond milk to create a light glaze. Bake until golden brown, 30 to 40 minutes.

Make the vegan horseradish sauce

  • Place the cashews in a large bowl and cover with boiling water. Let soak for at least 15 minutes, or longer if you have time.
  • Drain the cashews and place in a high-speed blender, along with the rest of the ingredients, and a pinch of salt. You can add more or less horseradish depending on how fiery you like it.
  • Serve the mushroom wellingtons with the horseradish sauce and any other veggies you like.

Nutrition

Serving: 1portion | Calories: 1076kcal | Carbohydrates: 80g | Protein: 24g | Fat: 77g | Saturated Fat: 16g | Monounsaturated Fat: 37g | Trans Fat: 1g | Sodium: 734mg | Fiber: 8g | Sugar: 9g