Preheat the oven to 180°C fan/200°C/gas 6. Blitz the pine nuts, parsley, water, lemon juice and 1 teaspoon of sea salt flakes in a high-speed blender until you have a thick, smooth green paste. It should look like very thick green hummus. Set aside.

Oil and line a 24–25cm pie dish or small roasting tin with baking paper. Lay over a sheet of filo pastry, brush it with oil, then lay another on it at a 90° angle. You’ll have a lot of overhang, but don’t worry about this yet. Repeat, so you have 4 layers of oiled pastry, then fold the overhang back to form the tart edges, scrumpling it a little if you wish.

Spread the pine nut mixture over the pastry base. Toss the mushrooms with the chopped sage, rosemary, oil and another teaspoon of sea salt, then scatter them evenly over the tart. Transfer to the oven and bake for 25 minutes, until the pastry is golden brown.

Squeeze over the lemon juice, scatter over a pinch of sea salt flakes and a little flat-leaf parsley, grind over a generous amount of black pepper, and serve.