The éclairs can be prepared the day before. If you choose to do this, it is important that they are kept in a dry place.
In a saucepan, mix the water, butter and salt.
Place on a low heat and mix with a wooden spoon.
Once the butter has melted, remove from the heat and add the flour. Mix vigorously to prevent lumps forming.
Once the pastry no longer sticks to the sides and has formed a ball, put the saucepan back on a very low heat to dry the pastry for 2 minutes, turning constantly.
Off the heat, add an egg and mix well. Repeat with each egg, adding them one by one. Work the pastry until it is very smooth.
Preheat the oven to 180°C.
Fill a smooth 1 cm piping bag with the choux pastry and pipe 8 strips of pastry 10 cm long onto a baking sheet covered in a sheet of baking paper.
Glaze the pastry strips with the whisked egg yoke and heat in the oven for 30 minutes, keeping a close eye on the color.
Remove the éclairs from the oven and leave to cool on a cooling rack.