Three-cheese and chive tart

Method

1. First make the pastry. Pulse the flour, cayenne pepper and salt in a food processor. Add the butter and whizz until the mixture has the texture of fine breadcrumbs. Transfer to a bowl and stir through the red leicester. Using a palette knife, mix in enough iced water (about 3 tbsp) to make the mixture start to gather in clumps. Knead briefly, then form into a flat disc, wrap in cling film and chill for 30 minutes.
2. Preheat a baking sheet in the oven to 220°C/fan200°C/gas 7.Roll out the pastry on a lightly floured surface to line a 23cm loose-bottomed tart tin. Trim and discard any excess pastry. Prick the base all over with a fork and chill once more for 15 minutes.
3. Line the pastry case with baking paper and baking beans or rice. Blind-bake for 15 minutes, remove the paper and beans/rice, then return to the oven for 5 minutes until golden and sandy-textured. Set aside. Reduce the oven temperature to 180°C/fan160°C/gas 4.
4. Meanwhile, heat the oil in a frying pan and fry the onion over a low heat until softened and golden. Add the garlic and cook for 1 minute more, then remove and cool. Mix the whole egg, yolks, crème fraîche, cream and mustard together in a jug. Season with a little sea salt and freshly ground black pepper. Stir through most of the cheese and all the chives.
5. Spoon the onion over the tart case. Pour the egg and cheese mixture over the top. Scatter over the remaining cheese, then bake in the oven for 20 minutes until golden. Remove and cool before slicing into wedges to serve.