Berry ripple ice lollies

Inspired by a recipe from the Waitrose magazine supplement, I made these yesterday,  my own version, a creamy custardy body with a mixed berry coulis through it.  Place your berries in a small saucepan (I had blackberries, blueberries, raspberries and strawberries) with some sugar - not too much, a tart coulis will better offset the sweetness of the main lolly. Leave on a gentle heat to dissolve the sugar and soften the berries, then push through a sieve to extract the coulis, leave to cool. meanwhile, make half a pint of vanilla custard, leave to cool until just warm and beat in half a tin of condensed milk. When both the coulis and the custard mix are cold, layer them in your lolly moulds, then stir very gently with a skewer. Freeze until solid.