Sift the flour. In a saucepan bring the milk, water, sugar, salt and butter to a boil.
Remove from heat and add flour all at once and incorporate mixing energetically with a wooden spoon or spatula until homogenous.
Return the saucepan over low heat and while stirring cook for 1 minute or two to pull out the moisture from the batter and until it pulls away from the sides of the pan. You will see some of the dough sticks to the bottom of the pan.
Transfer batter to a large bowl and allow to cool slightly. Add the eggs one at a time, carefully incorporating each into the batter using a wooden spoon, spatula or mixer. It will result in a smooth, homogenous batter that still holds its shape.
Fit a pastry bag with a large ½ inch (1cm) star tip and pipe the dough into 2 ¾-inch (7cm) strips on a parchment paper lined baking sheet.
Bake for 30-35 minutes until browned and puffed.
Prick each with a skewer to release steam and allow to cool on a wire rack.