Belgian vegetarian Vidé: warm, flaky puff pastry vol-au-vent cases filled with a velvety white wine and mushroom velouté, finished with cream, fresh lemon, and flat-leaf parsley.
Melt half the butter in a skillet over high heat. Sauté the sliced mushrooms for 6 minutes until golden brown and their liquid has evaporated; set aside.
Melt the remaining butter in a saucepan, stir in flour for 1 minute, then whisk in white wine and hot vegetable stock until a thick, smooth sauce forms.
Stir the double cream and lemon juice into the sauce, then fold in the sautéed mushrooms and chopped parsley, simmering for 2 minutes.
Warm the puff pastry cases in a 180°C oven for 5 minutes. Spoon the hot mushroom ragout generously into the cases until overflowing, placing pastry caps on top.