Adapted from Ottolenghi Test Kitchen, Shelf Love (Ebury Press) 

Method

• Preheat the oven to 180°C fan. Line the bottom and sides of a 23cm springform cake tin with baking parchment.
• Put the cauliflower on a large, parchment-lined baking tray and toss with the curry powder, half the oil, ½ teaspoon salt and a good grind of pepper. Roast for about 20 minutes, until cooked through and lightly coloured. Set aside, and turn oven down to 170°C fan.
• Meanwhile, make the béchamel. Put the cubed butter into a medium saucepan on a medium-high heat and, once melted, whisk in the flour and cook for 1–2 minutes – it should l start to smell nutty (like popcorn). Turn the heat down to medium and slowly add the milk a little at a time, whisking continuously to prevent any lumps, until incorporated and the sauce is smooth. Cook, whisking often, for about 7 minutes, until thickened slightly. Off the heat, stir in the garlic, mustard, cheese and ¼ teaspoon salt until the cheese has melted.
• Keep your filo sheets under a damp tea towel to prevent them from drying out. In a bowl,
• Combine the melted butter and the remaining 1 ½ tbs oil and keep to one side.
• One sheet at a time, brush the exposed side of the filo with the butter mixture and drape it into your prepared tin (buttered side up), pushing it down gently to fit. Continue in this way with the next filo sheet, brushing it with butter and then laying it over the bottom sheet, rotating slightly so the overhang drapes over the sides at a different angle. Do this with all six sheets.
• Spoon half the béchamel into the base and top with the roasted cauliflower florets. Spoon over the remaining béchamel, then crimp up the overhang so that it creates a messy ‘scrunched-up’ border around the edges, leaving the centre exposed.
• Brush the top of the filo border with the remaining butter mixture, then transfer the tin to a baking tray and bake for 30 minutes.
• Using a tea towel, carefully release the outer circle of the springform tin and bake for another 20–25 minutes, or until the sides are nicely coloured and everything is golden and bubbling. Leave to settle for 15 minutes.
• Top with the parsley and lemon zest and serve warm.