Rub the butter into the flour until it resembles fine breadcrumbs (or blitz in the food processor for a few seconds. Add just enough cold water to bring the mixture together into quite a firm dough (I used 4 tbsp).
Wrap in cling-film and chill for at least an hour.
Pre-heat the oven to 190 C/180 C Fan/ Gas 5/375 F
Roll out the pastry on a floured board and line a greased 20cm/8" sandwich cake tin or flan tin.
Bake blind for 12-15 minutes or until it's just starting to colour.
Remove from the oven and reduce the heat to 170 C/160 C Fan/ Gas 3/325 F
Heat 1 tbsp olive oil in a frying pan. Add the spinach leaves and Black pepper and allow to wilt for a minute or two. Remove from the heat.
Mix the eggs, cream and cheese together.
Spoon the spinach into the pastry cases. Pour the egg mixture over. Bake for 20-25 minutes or until the filling is golden brown and set firmly.