Preheat the grill to full whack. Place the whole peaches onto a snug-fitting baking tray and pop under the grill for 8 to 10 minutes, or until soft and blackened on top, then leave aside to cool.
Once cool, peel the skin off the peaches, then halve, discard the stones and tear the flesh into rough 2cm chunks.
Arrange the Parma ham on plates and crumble over the cheese. Finely slice the radicchio and scatter over with the peach chunks.
In a small bowl, mix 2 tablespoons balsamic with 4 tablespoons extra virgin olive oil and drizzle over the salad. Season lightly with sea salt and black pepper, before serving.