Preheat the oven to 180°C. Use the puff pastry squares to line four individual 12 cm pie tins, rolling the pastry out to make sure the edges hit the rims of the tins if necessary. Fork the pastry at the bottom, then line each pie case with baking paper and cover with baking beads or rice. Bake blind for 8–10 minutes, remove the beads and paper and bake again for 2–4 minutes, or until the pastry is dry to the touch. Remove from the oven and set aside to cool. Heat the oil in a heavy-based saucepan over a medium–low heat. Add the pumpkin, onion, ras el hanout and butter, cover with a lid and cook for 15 minutes, then remove the lid and cook for a further 10 minutes until the pumpkin is soft. Tip the cooked pumpkin mixture into a food processor, add the eggs, cream and milk powder, if using, and blitz until smooth. Press the mixture through a sieve to remove any lumps, then spoon it evenly into the four tart cases. Divide the haloumi chunks between the tarts, return to the oven and bake for a further 18–20 minutes, until the filling is set and the top is golden. Serve the tarts on their own, with a little green salad or the Mrs’ toasted couscous salad, or topped with a fried egg.