Step 1

Prepare the butternut squash: slice off the ends and discard. Next, cut the squash in half. Using a sharp vegetable peeler, peel off the skin and discard. Note: you can also use a sharp knife to cut off the skin.Use an ice cream scoop or spoon to scoop out the seeds and pulp. Discard.Finally, dice the butternut squash into 1-inch cubes.

Step 2

Preheat oven to 425 °F(220°C) and line a baking sheet with parchment paper. Transfer the diced butternut squash to the baking sheet and drizzle with the oil. Sprinkle with salt, and use your hands to coat the diced butternut squash with the oil. Spread the cubes into an even layer.

Step 3

Bake for 25-30 minutes or until the butternut squash is fork-tender. Remove from heat and set aside.

Step 4

Heat the butter in a large non-stick skillet over medium heat. Once melted, add the minced garlic and shallots, and sauté for 2-3 minutes.

Step 5

Next, add the diced mushrooms and sauté for another 5 minutes.

Step 6

Add the roasted butternut squash, cooked chestnuts, dried raisins, walnuts, soy sauce, herbs, black pepper, and salt. Stir to mix everything and cook for another 5 minutes. Remove from heat and taste the filling. Adjust the seasonings to taste.

Step 7

Using a large spatula, or potato masher, roughly mash about half of the filling. This step will help the filling hold together better and prevent it from crumbling.

Step 8

Preheat oven to 350 °F(175°C) and line a baking sheet with parchment paper.

Step 9

On a lightly floured surface, unroll the puff pastry. You should have a rectangle of about 12x8 inches. Arrange the filling in the center of the puff pastry and shape it into a long and tall log. Wrap the long sides of the pastry over the filling and lightly press to seal. Then, fold the top and bottom ends over it.Note: if you end up having too much puff pastry, simply use a knife or a pair of scissors to cut the excess.

Step 10

Carefully flip the Wellington and place it on the prepared baking sheet. Brush the top and sides with almond milk (or vegan butter). Next, using a sharp knife, make diagonal slits. Repeat in the other direction to create a pattern.

Step 11

Bake the Wellington for about 30 minutes or until golden brown. Let it sit for about 15 minutes before cutting and serving. Serve with mashed potatoes and/or gravy!