Cut the mango flesh into cubes or slices - whichever you prefer. Halve the passion fruit and scoop out the pulp and seeds. Slice the banana neatly.
Now you just have to assemble the trifle. Cut the sponge into wide fingers and spread each one with lemon curd. Put a double layer of these curd side up in the bottom of a glass bowl. Sprinkle with half the rum, the