Cook fruit, sugar, and butter in a saucepan over medium heat for 15 minutes.
Strain the mixture through a colander into a bowl for 10 minutes to collect 600ml of juice.
Simmer the juice in a saucepan for 15 minutes until reduced by half, then cool for 30 minutes.
Oil a 1.5 litre basin, line with cling film, and place a juice-dipped bread round at the bottom.
Line the basin sides with juice-dipped bread halves, ensuring they overlap slightly.
Mix half the remaining juice with the cooked fruit and spoon into the basin.
Cover the top with remaining juice-dipped bread and trim for a neat finish.
Seal with cling film, weight down with tins, and chill in the fridge overnight.
Turn out onto a plate, remove film, and brush white patches with reserved juice.