A very simple pudding. You use roughly the same quantity of cream as of fruit compote. The amount of sugar you need will vary according to the kind of fruit (or, in the case of rhubarb, vegetable). This fool includes about 20 greengages, two small punnets of blackberries, 2tbsps of caster sugar, 400ml of double cream, and 1tsp of vanilla essence.
Put about 50ml of water into a heavy saucepan, and throw in the greengages and blackberries with the sugar. Cover, bring to a simmer, and cook gently, stirring from time to time, until the fruit is very soft - no more than 15 minutes, probably. Force the compote through a sieve into another saucepan, pushing and stirring the fruit with a spoon.
Bring the sieved compote to a simmer again, and cook until it is lava-like in consistency, with big bubbles breaking the surface. Test for sweetness. Pour the compote into a bowl, and allow to cool. (It will thin the cream if it is hot.)
Whip the cream, with the vanilla if using, and stop as soon as it stiffens. (If you keep beating, it will become almost solid, and grainy too.)
Blend the cream and the compote, and chill for a couple of hours.