Soak sago in milk overnight. Next day butter a 1.5 litre pudding basin. Put fruit and dry ingredients into a large bowl and mix well. Tip in sago and milk. Lightly whisk eggs with the melted butter and stir into the fruit mix.

Fill basin just over two-thirds full. Cover with a doubled sheet of foil and tie with string under the rim of the basin. Stand basin on a wire rack or an enamel plate inside a stockpot and add boiling water to come two-thirds up sides of the basin. Cover the stockpot and boil for 3 hours, topping up the water level as necessary. The finished pudding will be dark and glossy. Serve hot with custard.

For the custard

Bring milk, cream and vanilla bean to simmering point in a heavy-based saucepan.

In a bowl, whisk egg yolks with sugar until light, then whisk in warm milk and cream. Return to rinsed-out pan and cook over a moderate heat for at least 10 minutes, stirring constantly with a wooden spoon until mixture thickens and coats the back of a spoon. Strain into a cold bowl, then scrape in some of the vanilla seeds from the vanilla pod.

Serve with plum pudding.

Tip: Rinse and dry the vanilla pod - it can be reused.