Heat the oven to 180C/fan 160C/gas 4.
Heat 1 tbsp olive oil in a frying pan and fry 6 chopped rashers of bacon for a minute or so until lightly cooked.
Beat 5 large eggs, a 284ml carton of single cream and 150ml milk together with a fork then add 140g finely grated gruyère cheese, a generous grating of nutmeg and plenty of seasoning.
Stir in half the bacon and carefully pour the mixture into the deep 24cm blind-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.