Slice prosciutto into quarters; wrap one piece around each water chestnut and secure with a toothpick. Place on foil-lined or parchment paper-lined baking sheet.
In small saucepan, heat apricot jam with rosemary over medium heat for 2 or 3 minutes or until melted; brush over prosciutto. Bake in oven at 375°F for 20 to 25 minutes or until edges of prosciutto are crisp and glaze is bubbling.

Recipe for Fiorucci by Laura Buckley