1. Preheat your oven to 350°F (175°C)

2. Take a large mixing bowl and mix cold water with confectioners sugar and flour until the dough forms

3. Roll the dough out on a floured surface to about 1/8 inch (3 mm) thick

4. Place it into a 9-inch (23 cm) tart pan with a removable bottom

5. Cut the edges and make sure the dough is pressed into the corners

6. Bake the crust for 15 to 20 minutes until it turns light golden

7. Let it cool down fully before adding the filling

8. In another bowl blend egg yolk and softened butter or margarine until smooth

9. Top the pie with thin lemon slices a light dusting of confectioners sugar and a few lemon balm leaves

10. Chill before serving and enjoy