Black and White Tart

I apologize for the slightly eighties ring to the title, but I can’t help myself. You could use any berries here, but I made this to wallow in the sheer beauty of the blackberries and whitecurrants of the last summer of the last century. And before you start mewing to yourself about the difficulties of unearthing such rare treasures, I should tell you that Sainsbury’s regularly stocks them in season. This is one of the easiest tarts you could make: a cheesecake base, the filling a mascarpon