Éclair (choux pastry)
Pour the water and milk into a saucepan.
Add the butter, sugar, and salt and bring to a boil.
Remove the pan from the heat and add the flour, stirring continuously avoiding lumps.
Place the pot back on low heat and stir vigorously stirring the mixture with a wooden spoon, until the dough combines and begins to come away from the sides of the pot (you will see a white film on the walls of the pot).
Preheat the oven to 400°F (200° C)
Add the eggs one by one to the cool mixture and mix well before adding the additional eggs, one at a time.
Spoon the dough into a “sac a poche” (pastry bag) and pipe the elongated shape onto the baking sheet.
Then with a damp finger, flatten the apex.
Bake until they and are golden brown on top.
Pistachio Cream
Blend the pistachios with the sugar in a blender until you get a paste, add half the milk, and continue to blend them.
In a saucepan, melt the butter and the chopped chocolate over low heat in the remaining milk.
Remove from the heater and add the pistachio paste and mix everything together.
Then with a hand mixer, blend everything together until you get a smooth and homogeneous cream.
White Glaze
To make the white glaze, put the powdered sugar in a bowl and add a spoonful of water at a time, mixing with a wooden spoon, until an average fluid batter is formed; at this point work it vigorously for a few minutes, after which your glaze will be ready to use.
Divide the batter in two and color one purple.
Assembling
Put the pistachio cream in a piping bag and stuff the éclairs.
Garnish with the white and purple glaze and sprinkle some pistachio grains on top