directions

• Heat a knob of butter in a large pot over a medium-high heat. Add the spinach with a teaspoon of water and steam for 2-3 minutes until just wilted. Drain well, squeezing excess water out.
• Cook the rice according to the package instructions. Drain and set aside to cool.
• Heat the oil in a pan over a medium heat. Cook the onion for 5-6 minutes until soft. Add the celery and carrot and cook for five minutes longer, stirring occasionally, until the vegetables are tender. Add the garlic and cook for one minute, then remove the mixture from the heat and set aside.
• Place the chestnuts in a large bowl and crush roughly with a potato masher. Add the spinach, rice, onion mixture, salt, cashews, hazelnuts, rosemary, thyme and Cheddar. Add one egg and mix to combine. Place in the fridge for 30 minutes.
• Preheat the oven to 180°C/160˚C fan/gas mark 4. Roll out the puff pastry into a rectangle about ¼cm thick.
• Place the filling mixture widthways in the centre of the sheet of pastry. Cut strips in the pastry at 2cm intervals, running from the edge of the filling to the pastry edges. Fold the two ends of the pastry rectangles up over the filling, then bring the strips of pastry over the top in alternating, overlapping layers. Transfer to a baking tray.
• Beat the remaining egg with one tablespoon of water and brush over the top. Roast for 35 minutes or until golden brown. Allow to sit for 4-5 minutes, then slice and serve.