Ottolenghi’s butternut crunch pie

Method

1. Heat the oven to 200°C fan/gas 7. Grease the base and sides of the cake tin with oil, then line with baking paper.
2. For the filling, heat 2 tbsp of the oil in a large sauté pan over a medium-high heat. Add the onions and 1⁄4 tsp salt, then turn down the heat to low and cook, stirring occasionally, until nicely caramelised (about 45-50 minutes). Remove from the heat and stir in the herbs, feta, lemon zest, 1⁄8 tsp salt and a good grind of pepper.
3. Meanwhile, line a large baking tray with baking paper. Add the butternut squash, cinnamon, remaining oil, 1⁄2 tsp salt and a good grind of pepper, then toss everything together. Bake for 30 minutes, flipping over the squash halfway through, or until cooked through and lightly coloured. Turn down the oven to 170°C fan/gas 5.
4. Put the filo sheets under a clean, slightly damp tea towel. Brush a sheet with some of the melted butter and sprinkle with 1⁄2 tsp of the caster sugar. Transfer to the prepared cake tin, pressing the sheet into the base and letting any excess hang over the sides. Repeat with 4 more sheets of filo (so 5 in total), rotating them slightly when you press them into the tin, so the excess hangs over at different angles.
5. Put the squash pieces in the base of the pie, overlapping them slightly. Top with the onion mixture, compressing it down. 6 Take another sheet of filo, brush it with melted butter and sprinkle with 1⁄2 tsp caster sugar. Scrunch it up, then arrange it on top of the exposed filling.
6. Repeat with the remaining 4 filo sheets to cover the filling completely. Fold in the overhang, scrunching it up in the same way, and brush with any remaining butter. Put the tin on a flat baking tray and bake for 50 minutes.
7. Meanwhile, put the chillies, vinegar and a tiny pinch of salt in a bowl. Mix to combine, then set aside to pickle lightly. 8 Remove the pie from the oven and use a tea towel to help release the tin, removing the outer ring and baking paper (leaving the pie on the base). Bake for another 25 minutes or until browned and caramelised all over. Remove from the oven and leave to cool slightly (about 15 minutes) before transferring to a plate or board. Dust with the icing sugar just before serving with the pickled chillies alongside.