1. Mix the flour and salt together in a bowl.
2. Add the sugar and shredded suet and blend well.
3. Gradually stir in the milk, blending until the mixture is firm.
4. Grease a 1 pint (600 ml) pudding basin.
5. Line the base with two thirds of the pastry and put the jam in the bottom.
6. Cover the pudding with the remaining pastry, then cover with greased greaseproof paper making a pleat across the top for the pudding to rise.
7. Secure the paper around the basin with string.
8. Place the basin over a saucepan of water and boil for 1 1/2 hours.
9. Turn out onto a warm serving dish and heat some extra jam or make custard to pour over the top.