Using a sharp knife, cut the melon in half, scoop out the seeds and discard. Cut each half into four. Remove the rind by slipping the knife between the melon flesh and rind, then cut the melon into bite-sized pieces
Peel the mango using a sharp knife or peeler. Slice the mango cheeks off either side of the large central flat stone, then cut the mango into cubes. Cut off the mango around the stone too.
Using a serrated knife, cut off the top and bottom of the orange, then cut away all the peel and pith. Cut between the orange segments to remove each piece.
Peel the papaya with a knife or potato peeler and then cut the fruit in half. Scoop out and discard the seeds and cut the fruit into pieces.
Cut the passion fruit in half and scoop out the seeds.
Put all the prepared fruit, except the raspberries, in a bowl, cover with cling film and put in the fridge, mixing from time to time.
Just before serving, add the fresh raspberries. Serve with chilled crème fraîche if liked.