Step 1

Preheat the oven to 180°C and line one or two large baking trays with baking paper (you will need to fit two pastry squares on them).

Step 2

Thinly slice the mushrooms and finely dice the shallot. In a large skillet, heat the butter and oil over medium-high heat. If your skillet is not very large you may need to cook the mushrooms in two batches (if so, use half the shallot, oil and butter for the first batch, then wipe down the pan and add the remainder for the second batch). When the butter is melting, add the shallot with a small pinch of sea salt and cook for a minute until it begins to turn golden. Add the mushrooms and cook for 5-10 minutes until they release their juice and become lovely and soft.

Step 3

Meanwhile, allow the pastry to defrost for the recommended length as per package instructions. Once defrosted (but not soggy! Best to undershoot it), place the pastry squares on the tray(s) lined with baking paper. Spread the crème fraîche evenly over the bases, leaving around 4cm free around the edge for folding. Add the mushrooms on top of the crème fraîche, then sprinkle over the thyme leaves and a scattering of finely grated parmesan cheese. Fold the edge over itself, pressing down to ensure it holds, and neatly tuck the corners.

Step 4

Bake in the oven for 20 minutes until the pastry is golden. Allow to cool slightly before serving with a leafy salad.