175g (6oz) plain flour, plus extra for dusting
85g (3oz) hard block margarine or chilled butter, cut into cubes
8 rashers of smoked dry cure bacon, chopped
5 large eggs
284ml carton single cream
140g Gruyère cheese, finely grated
generous grating of nutmeg
Salt and pepper
First make the pastry: tip the flour into a large mixing bowl. Add the margarine or butter and rub in gently with fingertips until the mixture resembles fine breadcrumbs. Add 3 tablespoons cold water until the pastry comes together in a ball.
Roll out the dough on a lightly floured surface and use it to line a 10in loose-bottomed flan tin. Ideally, use a fluted tin. Chill in the fridge for 30 minutes.
Meanwhile, preheat the oven to 220˚C. Prick the pastry case all over with a fork, to prevent air bubbles forming during baking. Line the base and sides with baking parchment and weigh it down with baking beans. Place on a baking sheet and bake for 10 minutes. Remove the beans and paper and bake the empty case for a further 10 minutes, or until the base is lightly browned. Trim the overhanging pastry.
Reduce the oven temperature to 180˚C. Crisp the bacon in a sauté pan over a medium heat for 10 minutes. Transfer to a bowl and leave the juices in the pan.
Place the onion in the pan and cook over a medium heat for 8 minutes or until golden.
Beat the eggs, cream and milk together with a fork then add the cheese, nutmeg and plenty of seasoning. Stir in the onion and most of the bacon and carefully pour the mixture into the baked pastry case then scatter over the remaining bacon.
Bake for 35-40 minutes until the filling is set, starting to turn golden and slightly puffed up above the pastry case. Allow to cool a little before removing from the tin. Serve warm or at room temperature, with a green salad.