Deep-dish Gruyère, spinach and bacon quiche with walnut pastry

Method

1. First, make the pastry. Put the flour, walnuts and salt in a food processor and pulse to combine. Add the butter and pulse until it resembles breadcrumbs.
2. Add the egg yolk and pulse, gradually adding the water until the mixture just comes together. Tip out onto a lightly floured surface, bring together with your hands and knead briefly. Shape into a disc, wrap in cling film, then chill for 15 minutes.
3. Preheat the oven to 200°C/fan 180°C/gas 6. Roll out the pastry on a lightly floured surface to the thickness of a pound coin and use to line a 23cm loose-bottomed sandwich tin. Chill for 10 minutes.
4. Line the pastry case with baking paper and baking beans or rice, then blind-bake (see our how-to video below) for 15 minutes. Remove the paper and beans/rice, then bake for 5-10 minutes more until golden. Remove from the oven. Turn the oven down to 180°C/fan160°C/gas 4.
5. Meanwhile, fry the bacon in a frying pan over a medium heat until crispy, then use a slotted spoon to transfer onto kitchen paper. Fry the onion in the bacon fat until golden and soft, then add the spinach and allow to wilt. Transfer to a sieve to drain, using the back of a spoon to extract as much liquid as you can.
6. Whisk the eggs, egg yolks, cream, gruyère and parsley in a jug, then season. Spoon the spinach and onion over the pastry base, scatter over the bacon, then top with the egg mixture. Bake for 50 minutes until golden.
7. Remove from the oven, take out of the tin, then put on a wire rack to cool a little. While still warm, return to the tin and wrap in foil to transport.