Sift flour then measure and set aside
Place butter, water, milk, salt, and sugar into a saucepan over medium heat
As soon as the mixture starts to boil remove from heat, add the flour in one go, and whisk vigorously with a Rubber spatula until it forms one smooth ball and flour bits are not visible
Place the saucepan back to the stove and cook the dough for 3-5 min over medium heat mixing constantly. During this time water will evaporates from the dough and there should be a thin skin formed on the bottom up the saucepan
Transfer the dough into the bowl of your Stand mixer and start whisking on low seead for a minute for the dough to cool a bit (use the paddle attachement)
Start adding lightly whisked eggs onto the dough while the mixer is on. Only add a small amount of egg at a time and let the mixer incorporate the egg before adding in more. The dough will come together and should reach a glossy, pipeable consistency.
The dough is ready when it slowly falls down from the paddle attachment in a V shape. Slowly is key here, it should not be too runny. Depending on how much you dried the dough at the previous cooking stage and the flour you use, the exact quantity of egg will need somewhat your judgement
Move the dough into a pastry bag fitted with French star nozzle tip (0.5cm / 1.3cm in diameter) and rest the dough in the fridge for 1-2 hours
Once the dough is rested, with the help of the French star nozzle tip pipe 14 equal size eclairs on Perforated "air" baking mat leaving enough space in between them as they will puff.
Alternatively, cover a baking sheet with parchment paper, and pipe the choux dough onto the paper.
Dust the piped dough with icing sugar, that also helps to avoid cracks. Place the tray into the freezer for 30 min at least before baking you can also freeze the dough at this point for a longer time
Pre-heat oven to 200 C / 392 F (no fan)
Lower oven temperature to 170 C / 338 F (no fan) and bake the eclairs for 40 min. Do not open the oven door in the first 30 min. If you are baking it the first time it is a good idea to take one eclair out of the oven at 40 min and check its consistency. If it is golden in colour, nicely puffed up, does not deflate on room temperature and the middle of the eclair is not raw (it is ok if it's a bit wet, it will dry while cooling down) then it is considered to be done
Cool the eclairs on the perforated air mat
Fill with chocolate or vanilla bean pastry cream. Use my recipes in here