Heat lime curd ingredients in a saucepan over low heat for 12 minutes until thick.
Strain the lime curd through a sieve and cool before jarring.
Heat milk and cream until boiling, then remove from heat.
Whisk eggs, salt, and sugar together, then slowly whisk in the hot milk mixture.
Butter bread slices and spread 12 tablespoons of lime curd on both sides.
Layer bread slices in a greased dish, sprinkling cranberries and rum between layers.
Pour the custard mixture over the bread and soak for one hour.
Preheat oven to 180°C.
Place pudding in a roasting tray filled with boiling water to one-third depth.
Bake for 45 minutes until the custard sets and the top is golden-brown.
Cool the pudding for 10 minutes after removing it from the oven.
Melt redcurrant jelly with water and brush over the pudding as a glaze.
Serve with whipped cream.