Sift together flour, salt, and baking powder in a large bowl.

Stir in vegetable suet, brown sugar, currants, lemon zest, and mixed spice.

Add milk gradually until a soft dough forms.

Shape the dough into a log.

Wrap the log loosely in buttered cling film.

Wrap again in muslin and secure with string.

Simmer in a large pot of boiling water for 2 hours, ensuring the pudding is fully submerged.

Alternatively, if using a cylindrical mould, line with buttered greaseproof paper.

Place the dough in the mould and steam for 2 1/2 hours.

Remove wrappings.

Cut the pudding into 3cm slices.

Serve each slice with a knob of butter and a drizzle of golden syrup.

Serve with custard or double cream if desired.