Drain the cashews and add them to the jar of a blender along with 120ml (½ cup) cold water. Blend on high for 1-2 minutes until very smooth. Transfer the cashew cream to a small bowl and set aside (see note 2).
Add 2 tablespoons of olive oil to a large skillet and set over medium heat. Once shimmering, add the shallot and garlic along with a generous pinch of salt. Cook, stirring frequently, until softened - about 2 minutes.
Add the peppercorns and stir to combine. Remove the pan from the heat and pour over the brandy. Return the pan to the heat and cook, stirring frequently, until the alcohol has cooked off and it has significantly reduced.
Sprinkle over the flour and stir to combine. Whisking constantly, slowly pour in the vegetable stock. Bring to a simmer and whisk in 2 tablespoons of the cashew cream and the miso paste.
Allow to simmer until the sauce reduces slightly and thickens enough to coat the back of a spoon - only a few minutes. Stir in the vinegar and taste to adjust for seasoning, adding salt where needed. Serve immediately.
