• 1 quantity puff pastry
• egg wash, for brushing
• 600 g (1 lb 5 oz) in-season mushrooms
• 125 ml (4 fl oz/½ cup) olive oil
• 3 rosemary sprigs, leaves picked
• 8 thyme sprigs, leaves picked
• 250 g (9 oz/1 cup) caramelised onion
• 2 balls of buffalo mozzarella, cut into thirds

To make the bases, roll out the puff pastry to make a 25 x 38 cm (10 x 15 inch) rectangle, about 3 mm (⅛ inch) thick. Trim the edges and cut the pastry into 12 cm (4½ inch) squares — you should make six squares in total. Remember, when cutting puff pastry do not drag the knife through the pastry, cut the pastry from the top down. Lay the squares on a baking tray lined with baking paper, leaving a 3 cm (1¼ inch) space between each one. Brush the edges of each square with egg wash.

Preheat the oven to its highest temperature. To clean the mushrooms, remove the stalk and if they are covered in dirt run them under cold water. Use a small brush to paint the mushrooms with olive oil and place on a baking tray lined with baking paper. Sprinkle the rosemary and thyme over the mushrooms and cook in the oven for 7–10 minutes, or until the mushrooms are almost tender. Set aside and allow to cool.

Spread 2 tablespoons of caramelised onion over each pastry piece, leaving a 2 cm (¾ inch) border around the edges. Divide the mushrooms between the squares — if they are too big, cut them in half and arrange them over the onions. Season with salt and freshly ground black pepper, to taste.

Cook the pissaladière for 15 minutes, turning the tray after 10 minutes, until the base is cooked through. Allow to cool slightly on the trays before serving.