Ingredients

Step by step

1. Preheat the oven to 180°C, fan 160°C, gas 4. Grease and line a 23cm springform tin. Fill a medium saucepan to a depth of 1cm with salted boiling water, add the squash, cover and cook for 5-7 minutes until tender. Drain any excess water then blend with an electric hand blender. Set aside.
2. Pour the polenta into a saucepan with 600ml salted boiling water and put over a medium heat. Cook, whisking constantly, for 2 minutes, until the water has been absorbed and the polenta is thick. Add the squash purée and continue whisking for 6 minutes, until the mixture is very thick and sticky. Remove from the heat and stir in the butter, Parmesan and one of the eggs.
3. Transfer the polenta mix to the tin and spread out with a rubber spatula, flattening it out at the base and leaving a higher level of the mixture around the edges. Leave to cool for a few minutes, then, using the spatula (or your hands), press the mixture up the sides of the pan. Bake for 30 minutes until the crust is dry.
4. Meanwhile, heat the oil in a large frying pan (with a lid), add the onion and sweat for 2-3 minutes, until translucent. Add the spinach and 2 tablespoons of water to the pan, cover and cook for a few minutes until the spinach has wilted. Drain in a large sieve, pressing down with the back of a spoon to remove any excess moisture.
5. Beat the remaining eggs in a large bowl, add the spinach, onion, feta, milk and cream. Season to taste then pour into the tart case. Bake for 35-40 minutes until set (you may need to cover with foil for the final 5 minutes of cooking time if it's getting too brown). Allow to cool in the tin for 15 minutes then remove from the tin and allow to cool for a further 15 minutes before serving.
6. Watch this...

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