This is a good recipe to use up a glut of Marrows and Lemons. I've made it many many times and it tastes just like lemon curd...only difference is you are using the marrow as bulk instead of eggs.
1.8kg/4lb peeled, seeded and cubed marrow
1.6kg/3lb 8oz granulated sugar
8oz butter
6 lemons
Steam the marrow until tender.
Strain well and leave to drain overnight.
The following day mash into a smooth puree and put into a preserving pan.
Add the butter, sugar and juice and grated rind of the lemons.
Heat gently, stirring, until all the sugar has dissolved.
Boil for 20mins, stirring all the time.
Bottle into warmed jam jars.
This recipe will make about 6lb jars and will keep for up to a year in a cool place.