To begin, lightly grease a 1-litre pudding basin with butter. Cut a round of baking parchment to line the base. This prevents sticking. Move to mixing the dry ingredients.

In a large bowl, combine the self-raising flour, shredded suet, caster sugar, currants, and lemon zest. Stir well to evenly distribute the fruit. Transition to adding liquid.

Gradually add cold milk to the dry mixture, stirring until a soft but not sticky dough forms. If too dry, add a splash more milk. Move to transferring the mixture.

Spoon the mixture into the prepared basin, pressing gently to settle it evenly. Leave about 2 cm at the top to allow for expansion during steaming. Prepare the cover next.

Place a sheet of baking parchment over the basin, then cover with foil. Tie securely with string around the rim. Fold excess foil upwards to keep water from seeping in. Transition to steaming setup.

Place an upturned saucer or trivet inside a large pot. Set the basin on top and pour in boiling water to reach halfway up the sides. Cover the pot with a lid. Proceed to steaming.

Steam gently for about 1 hour 45 minutes, topping up with boiling water as needed. Keep the lid on to maintain consistent heat. Move to checking doneness.

Insert a skewer into the pudding centre. If it comes out clean, the pudding is ready. Carefully lift the basin out and allow it to stand for a few minutes. Transition to unmoulding.

Remove the foil and parchment. Run a knife around the edge of the basin, then invert onto a warm serving plate. The pudding should slide out smoothly. Transition to serving.

Slice the pudding into generous portions and serve hot with warm custard or cream. Presentation tip: dust lightly with icing sugar before serving for a traditional touch.