Place the porcini mushrooms in a small bowl and cover with the boiling water. Let stand for 15 minutes with a plate covering the bowl, so that the mushrooms rehydrate.

Warm the olive oil in a skillet over medium heat for 90 seconds. Once the oil is hot, ddd the onion and sauté for 6 minutes, until softened and lightly golden.

Add the garlic and grated parsnip, and continue to sauté for 4 minutes to soften the parsnips.

Stir in the rehydrated porcini mushrooms and all of their soaking liquid along with the sausage, Dijon mustard, and red wine. Cook for 6-8 minutes, or until almost all of the liquid has absorbed or evaporated.

Transfer to a food processor, adding the miso paste and flour, and pulse until mostly smooth. Let the filling cool completely.

Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper. Spread the puff pastry dough out onto a very lightly floured work surface. Cut each 10 inch sheet into 4 equal squares.

On one side of each square, make many little slits in the dough using the tip of a sharp paring knife (if you are going for the classic Greggs sausage roll look).

Divide the the cooled filling and spread it in a thin straight line in the center of the other half of the dough squares, opposite to the sides with the slits.

Fold the side with the slits over the filling, then press the edges tother to seal along the seam. If you want smaller, hors d’oeuvres size sausage rolls, cut the rectangular rolls into smaller bite size portions.

Arrange the rolls neatly on the prepared baking sheet. Whisk the plant-based milk, maple syrup, and Dijon mustard together in a small bowl, then brush evenly over the tops of the rolls.

Bake for 22 minutes, or until puffed and golden. Serve warm.