Preheat oven to 190C

Place the sliced mushrooms, butter, the leaves from four sprigs of thyme and garlic in a medium pan and saute over medium heat until the mushrooms start to caramelise and all the juices have reduced. Leave to cool.

Using a large dinner plate as a template, cut out a large round circle of pastry and place it onto a baking tray lined with baking paper.

Using a knife, score (but not cut through) a smaller circle, approx 1.5cms in from all edges of the pastry.

Spoon the cooked mushrooms into the inner circle and spread evenly inside this circle. Break of small pieces of goats cheese and dollop these evenly over the mushrooms.

Top the mushroom and cheese with spinach leaves.

Place the sliced potatoes carefully in a circular pattern over the mushroom, cheese and spinach layer, overlaying each potato piece with the one next to it.

Using a pastry brush, brush the top of the potato slices with melted butter and the edges of the pastry.

Sprinkle with salt and the remaining thyme leaves.

Place in the oven and bake for 30mins until the pastry and potato slices are golden brown.

Serve hot or warm.