Make up the pastry using the rubbing-in method and chill for 15 minutes. Remove the chilled pastry from the fridge and use to line the flan tin. Allow a little extra pastry to hang over the sides of the tin, and bake blind for 10 minutes at 200`c. Leave to cool before trimming the excess pastry off the edge of the flan case. Meanwhile, put the sliced mushrooms on a baking tray with a glug of oil and the thyme. Season with salt and pepper and bake in the oven for just 5 minutes. Place the butter and spinach leaves in a pan and heat to wilt the spinach for a few minutes. Add in a generous pinch of nutmeg and remove from the heat. In a bowl, mix together the ricotta cheese, grated Parmesan and the wholegrain mustard and spread into the bottom of the baked pastry case. Pile the cooked spinach on top, and then the cooked mushrooms (it is important that no juices are added) finally, mix together the eggs and double cream. Season well with salt and pepper, and pour all over the mushrooms. Bake in the oven at 180`c, for about 40 minutes. Serve the vegetarian tart cut into wedges, either hot or cold.

Suggested accompanying wine: DELICATA Pjazza Regina White I.G.T. Maltese Islands