tbsp (85g) unsalted butter, plus extra to grease
cup (100g) all-purpose flour
pinch of salt
medium eggs, beaten
oz (lOOg) prosciutto, minced
sage leaves, finely shredded
oz (40mg) Parmesan, finely grated
Heat the oven to 400°F (200°C). Put the butter and scant 1 cup (220ml) water into a heavy pan. Heat slowly to melt the butter, then turn up the heat and bring to a rolling boil. Meanwhile, sift the flour and salt together. As soon as the liquid comes up to a boil, tip in all the flour and salt and take the pan off the heat. Beat vigorously with a wooden spoon until the mixture comes together as a paste and leaves the sides of the pan. Spread on a plate and let cool. Return the paste to the pan (or place in a bowl) and beat in the eggs, a little at a time, until soft, shiny, and smooth. The mixture should have a dropping consistency (you may not need all of the egg). Beat in the chopped prosciutto, sage, and Parmesan until evenly incorporated. Lightly grease a large baking sheet. Spoon the mixture into a pastry bag fitted with a 1/2-inch (1-1.5-cm) plain tip and pipe into small 1 1/4 - 1 1/2-inch (3-4-cm) circles on the baking sheet, spacing them about 2 inches (5cm) apart to leave room for expansion. Bake for 20 to 25 minutes or until the pastries are well risen and golden brown. Serve immediately or keep warm in a low oven.