Blackberry Mousse

A little late for picking blackberries now as we are well past Michelmas, but if you have any saved or frozen then...
Wash about 1/2 kilo of Blackberries and place the best ones to one side for decoration later.
Put the rest into a pan with a dash of water and heat gently until they release their juices.
While that is cooking prepare some gelatine (either leave or powder).
Mash the blackberries in the pan and pass them through a fine sieve into a bowl pushing through as much juice and pulp as you can with a wooden spoon.
Pour the juice into a clean pan and add a some lemon juice (about 1/2 a lemon)- bring to a simmer them remove from the heat and stir in the gelatine. Set aside to cool.
Mix 3 eggs in a bowl with 100g of caster sugar until mousse like and while continuing to whisk slowly add the cooled juice and then 150ml of eith creme fresh double or soured cream or a comb of either.
Pour into glasses and put in the fridge to set.
Before serving decorate with the reserved blackberries.