Judith in France wrote:
Haver you tried cooking rhubarb, no sugar; make a sweet custard and
whizz the two together I call it Rhubarb Fool, but that's my own name
for

I quite often cook rhubarb without sugar, depending on what I'm going
to do with it. If it's for a pie, I add sugar, if it's for a crumble
or cake topping, which will be sweet, I don't, or lightly sugar it.