Christmas Pudding I

Combine grated carrot, grated potato, soft breadcrumbs, raisins, currants, and brown sugar in a large mixing bowl.

Cream margarine with the carrot-potato mixture until well blended, then add sour milk and stir to combine.

Dissolve baking soda in the sour milk mixture and fold gently into the pudding batter.

Sift flour, salt, cinnamon, nutmeg, and allspice together in a separate bowl.

Fold dry ingredients into the pudding mixture until just combined, being careful not to overmix.

Fill a buttered pudding basin or steamed mold three-quarters full with the batter, leaving room for the mixture to rise during cooking.

Cover the pudding basin tightly with buttered parchment paper and then foil, securing with kitchen string to prevent steam from entering.

Place the covered pudding basin in a larger pot filled with boiling water so that the water reaches halfway up the sides of the basin (a water bath).

Steam the pudding for 2 hours, checking the water level occasionally and adding more boiling water as needed to maintain the proper level.

Carefully remove the basin from the water bath and allow it to cool for 10 minutes before unmolding onto a serving plate.

Serve the Christmas pudding warm, optionally with custard, brandy butter, or cream.