85 g (3oz) hard block margarine or chilled butter, cut into cubes
175 g (6oz) plain flour, plus extra for dusting
salt and freshly ground black pepper
250 ml (9fl oz) single cream
2 large eggs
125 g (41⁄2oz) Gruyere cheese, grated
1 onion, peeled and chopped
175 g (6oz) unsmoked streaky bacon rashers, rinds removed, cut into strips