1. Preheat the oven to gas 7, 220°C, fan 200°C. Put the spinach in a heatproof bowl and pour over a kettleful of boiling water; set aside to defrost.
2. Meanwhile, heat 1 tbsp oil in a frying pan over a medium heat and fry the vegetable soup mix for 5 mins until tender. Stir in the garlic and thyme, fry for 1 min, then remove from the heat.
3. Drain the spinach through a sieve, then squeeze to remove the excess water. Stir through the softened veg, add the cheese and mix well with plenty of black pepper. Set aside for 5 mins.
4. Unroll the pastry on the baking paper it comes on, then cut into 4 rectangles. Spoon the filling over half of each rectangle, leaving a 1cm border. Pull the empty side over the filling and crimp the border with a fork to seal. Transfer to a baking sheet (still on the baking paper), make a small steam hole in each parcel with a knife, then bake for 20 mins until golden and puffed.
5. Whisk the lemon juice with the remaining 1 tbsp oil in a bowl. Toss in the cucumber, tomatoes and onion. Serve alongside the turnovers.
Tip: Make the turnovers up to 24 hrs ahead and keep in the fridge. They can also be frozen for up to 3 months, then baked from frozen.
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Freezing and defrosting guidelines
In order to enjoy optimum flavour and quality, frozen items are best used within 3 months of their freezing date. For more tips on freezing and defrosting food, read our article Love Your Freezer.