Vegan Mushroom Bouchées à la Reine

Place the dried porcini in a heatproof bowl and pour over the boiling water; set aside to soak. Drain the soaked cashews and place them in a blender. Finely dice the shallots, mince the garlic, and measure out the remaining ingredients.

After 20 minutes, lift the porcini from their soaking liquid with a slotted spoon and roughly chop them. Pour the soaking liquid through a fine sieve lined with kitchen paper, leaving any grit behind.

Add 200 ml of the strained porcini liquid to the blender with the cashews and blend on high for 2 minutes until completely smooth. Set the cashew cream aside.

Heat 2 tablespoons of olive oil in a large, wide skillet over high heat until shimmering. Add the cremini and chestnut mushrooms in a single layer and cook without stirring for 4 minutes until deeply golden on one side.

Stir the mushrooms, add the chopped porcini, and continue cooking for 3 minutes until all moisture has evaporated and the mushrooms are well browned throughout.

Reduce the heat to medium, push the mushrooms to the side of the pan, and add the remaining tablespoon of olive oil. Add the shallots and cook for 3 minutes until softened and translucent.

Add the garlic and thyme and cook for 1 minute until fragrant.

Pour in the white wine and cook for 2 minutes, scraping up any browned bits from the base of the pan, until the wine is almost fully absorbed.

Transfer the mushroom mixture to a bowl and wipe out the pan.

Melt the vegan butter in the same pan over medium heat. Add the flour and whisk constantly for 2 minutes until the roux smells biscuity and turns a pale straw colour.

Add the oat milk in a steady stream, whisking continuously, then cook for 4 minutes, still whisking, until the béchamel is thick enough to coat the back of a spoon.

Stir in the cashew cream, Dijon mustard, nutmeg, salt, and white pepper, then cook for a further 2 minutes, stirring, until glossy and velvety.

Fold the mushroom mixture into the béchamel along with half the parsley and the lemon juice. Taste and adjust the seasoning.

Preheat the oven to 180°C (fan 160°C / gas 4). Arrange the vol-au-vent shells on a baking tray and warm in the oven for 6 minutes until heated through and crisp.

Remove the pastry lids, spoon the mushroom béchamel generously into each shell so it mounds above the rim, then replace the lids at an angle. Scatter with the remaining parsley and serve immediately.