In a large mixing bowl, combine all the breadcrumbs, flour, sugar, suet and salt

Add the raisins, grated apples and grated lemon zest

Stir thoroughly to combine well

Beat the egg into the milk and stir into the mixture

Pack the mixture into a well-greased pudding basin

Cover the basin tightly with a sheet of baking parchment, then with a sheet of foil, make a pleat in the centre and secure with string

Boil a kettle and pour the boiling water into a saucepan, about half full, place it on a medium heat and, when it comes back to the boil, fit a steamer over the top

Steam the pudding for 2 hours, checking every so often that the water in the saucepan hasn't all evaporated away

Remove the sheets of foil & baking parchment. Place an upturned plate on the top, quickly flip over and carefully lift off the pudding bowl