Mangoes are not native to Italy, and absolute fidelity to indigenous ingredients would suggest you do this dish with peaches. If you can buy peaches that were picked ripe and are succulently sweet, forget the mangoes. I never see such peaches, except for a week or two in August, so for the rest of the year mangoes, their exotic flavor and texture notwithstanding, are a more desirable choice. They are usually least expensive when already ripe and ready to use. If they are still firm, let them ripen for 2 to 4 days at room temperature, until they begin to give under light pressure from your thumb.
