Add lemon rind, salt and sifted flour and baking powder. Mix well.
Grease a small pudding bowl or pyrex bowl.
Cover with greased paper and tie down.
Steam for one and a half hours.
Once cooked, use a knife to carefully free the pudding from the edges of the bowl before turning out onto a plate.
Whisk creme fraiche and custard together.
Pour over pudding and top with a slice of lemon.
If you don't have a steamer, put a small heatproof dish in the bottom of a saucepan. Fill with water to just below the top of the small dish and bring to the boil. Sit pudding bowl on top of small dish, turn down to a simmer and cover.