Place a large saucepan over a high heat, add the butter and once this has turned nut brown, add a dash of Extra Virgin Olive Oil to inhibit burning.

Add the mushrooms and cook for four to five minutes. Add the Verjuice and cook until absorbed. Sprinkle the thyme and flour over the mixture and cook for a further two minutes.

Gradually stir in the hot stock, followed by the cream. Reduce the heat and gently simmer until the mixture has thickened. Season to taste.

To make the pastry, follow the sour cream pastry recipe listed and add Gruyere cheese to the mixture with the sour cream.

Once chilled, roll the pastry to three millimetres thick and cut it to line an eighteen centimetre spring form tin with a six centimetre high side, leaving a ‘lip’ over the edge. Cut out a smaller round – this is the pie lid.

Fill the case with the chilled mushroom and thyme mixture. Egg wash the pastry lip and seal the lid in place. Trim the pastry and score the top of the pie. Egg wash the top of the pie and refrigerate for twenty minutes.

Preheat the oven temperature to 220C.

Place the pie onto a flat baking tray and place the pie into the oven to bake for twenty minutes. Reduce oven to 180C and bake for a further five to ten minutes until golden brown.

Remove from oven. Allow to cool slightly in the pan for five minutes to stop it crumbling when cutting. Remove the pie from the pie dish and serve.