I call this grown-up radicchio salad because radicchio is not for everyone. As a general rule, children are more sensitive to the bitter taste, so grown-ups are more likely to appreciate bitter leaves in their meal. This salad is all about contrast and complement. The sweetness of the sultanas mellow down the radicchio’s bitterness. The saltiness of the cheese and the prosciutto counter-balance the sweetness. Finally, the different textures, from the crunchiness of the radicchio to the bite of the pine nuts and the softness of the boiled eggs, complement each other. If you want to up your grown-up game, go ahead and soak the sultanas in pisco or grappa…