- 1 tbsp extra-virgin olive oil
- 45g butter
- 1 large red onion, very thinly sliced
- Large pinch of caster sugar
- 500g mixed wild and chestnut mushrooms, trimmed and thinly sliced
- 25g mascarpone
- 100ml double cream
- 2 large eggs, beaten
- 50g Grana Padano, finely grated
- 1 tbsp chopped fresh tarragon
- 2 tbsp chopped fresh flatleaf parsley
For the pastry case
- 225g plain flour, plus extra for dusting
- 65g chilled butter, cut into pieces, plus extra for greasing
- 65g chilled lard, cut into pieces
- 40g Grana Padano, finely grated
- For the pastry, sift the flour and a pinch of salt into a food processor. Add the butter and lard and whizz until it resembles fine breadcrumbs. Stir in the cheese, then 2 tablespoons cold water and mix until the pastry comes together into a ball.
- Turn out onto a lightly floured surface and knead briefly until smooth. Lightly grease a 23cm round x 4cm deep loose-bottomed flan tin. Thinly roll out the pastry on the floured surface and use to line the flan tin. Chill for 20 minutes.
- Preheat the oven to 200°C/fan180°C/gas 6. Line the pastry with baking paper and beans and bake for 15 minutes. Remove the paper and beans and return to the oven for 5 minutes, until the pastry is pale-golden.
- Meanwhile, heat the oil and 15g butter in a large frying pan over a medium heat. Add the onion, sugar and some seasoning and cook for 10 minutes, stirring, until soft and lightly caramelised. Tip into a large bowl.
- Melt another 15g butter in the pan, add half the mushrooms and cook over a high heat for 2-3 minutes, until softened and excess moisture has evaporated. Season and tip into the bowl with the onion. Repeat with the remaining butter and mushrooms. Set aside to cool slightly.
- In a bowl, mix the mascarpone with the cream until smooth, then mix in the eggs and half of the grated cheese. Stir into the mushroom and onion mixture with the tarragon, parsley and some seasoning.
- Spoon the mixture into the pastry case and scatter with the remaining cheese. Bake for 25-30 minutes, until lightly golden. Set aside for 10 minutes, then serve with salad.