Serves 4
1 cup gruyere, grated
½ cup parmesan, grated
¾ cup mascarpone
1 tbsp Dijon mustard
1 tbsp sage leaves, chopped,
plus 16 whole leaves
8 thick slices white bread
butter, for spreading
8 slices prosciutto
Place gruyere, parmesan, mascarpone, mustard, and chopped sage in a large bowl. Season with sea salt and freshly ground black pepper and mix to combine. Divide mixture evenly among 4 slices of bread and top with remaining slices.
Spread both sides of the sandwich with butter and top with whole sage leaves. Wrap sandwiches in prosciutto and cook in a nonstick saucepan over medium heat for about 3 minutes on each side, or until golden and melted. Sprinkle with sea salt and serve.