Put the butter in a saucepan with 200 ml of water and let it melt over a gentle heat. Now increase the heat and bring to a boil. Meanwhile, sift the flour, sugar and salt into a bowl. Take the saucepan off the heat, add the flour and stir with a wooden spoon until a firm, smooth paste is formed. Beat until it comes away from the edges of the pan and forms a ball, then remove from the heat and leave to cool for 10 minutes.
Preheat the oven to 200C/400F/gas mark 6. Add the eggs to the dough a little at a time, beating well after each addition, until the mixture is smooth and glossy (you may not need all the egg). With two teaspoons place little round balls the size of walnuts on baking trays lined with greaseproof baking paper. Bake for 20–30 minutes; do not open the oven door for the first 10 minutes or the pastry may not rise. The pastries are done when they are golden brown and firm.
Transfer to a wire rack and, with a sharp knife, pierce holes in the side of each to let the steam out and leave to cool. Once cool, cut the choux pastry in half and place a slice of the Castello Pineapple Halo cheese inside the choux pastry. Then to make the icing: mix the grated ginger with sugar and water, whisk well, and decorate the choux pastry with the icing. Let them sit for 5 minutes before serving.