Method

• 1.
  Generously grease a 1 litre/34 fl oz pudding basin (ovenproof bowl) with butter, then sprinkle the bowl with the extra sugar and coat it by rotating the bowl and covering the butter completely.
• 2.
  Put the flour, baking powder, suet, currants, the 80 g/3 oz sugar and the grated lemon zest into a large bowl and mix thoroughly until combined. Gradually stir in 200 ml/7 fl oz of the milk until it is the consistency of a thick cake batter, adding extra milk if needed. Spoon the batter into the prepared basin. Cover with a lid, or make one from a large pleated square made from a double layer of baking (parchment) paper and aluminium foil, and secure it around the top of the pudding basin with kitchen string.
• 3.
  Put the basin into a steamer and steam for 1 1/2–2 hours. Alternatively, put an inverted saucer into a large saucepan. Cover the saucer with a small square of muslin (cheesecloth) and set the basin on top, then fill the saucepan a third full with water. Bring to the boil, then reduce the heat and simmer for 1 1/2–2 hours. Make sure that you check and top up (top off) the water level as necessary halfway through cooking. The pudding is ready when a skewer or toothpick inserted into the sponge comes out clean.
• 4.
  Remove the pudding from the steamer and leave to stand for 5–10 minutes, then turn out onto a large plate and serve with custard.