Cut the peaches into slices approximately 7-8 mm thick. In a pan, heat the butter, place the peaches on top and cook for a few minutes. Gently turn them over using two spatulas and continue to cook for another 2 to 3 minutes. Season with some freshly ground black pepper, remove from the heat and leave to cool down slightly. Then, arrange the peaches on the serving dish and leave to cool completely.
With a mixer, blend the Gorgonzola together with the cream until you get a creamy mixture similar to whipped cream. Put the Gorgonzola mousse into a piping bag and place in the fridge to cool down. Just before serving, add a whirl of mousse on top of each slice of peach.