Heat the butter, water, salt and sugar in a pan.

As soon as everything has melted, pour in all the flour at once and mix well with a wooden spoon until the dough no longer sticks to the spoon or the pan.

Beat the eggs. Turn off the heat under the pan and add the beaten eggs in several batches, mixing each time until smooth. Stop when the right texture is reached (when spooning dough, a horn should fall a little but not completely), even if it means leaving a little egg (or adding more if necessary). The eggs are the adjustment variable in this recipe.

Butter a baking sheet, then arrange the dough in heaps for the choux, and in lines for the eclairs. Use a piping bag or simply two spoons.

Bake in the oven (pre-heated at 190 C, conventional heat, not fan heat) for 20 to 25 minutes. A little trick to check the cooking: the choux must resist pressure from your finger (or spoon, if you are afraid of burning yourself!).

Prepare the Pastry cream: heat the milk, salt and vanilla in a pan.

While the milk is heating, beat the sugar and eggs in a large bowl with a wooden spoon until the mixture turns white. Stir in the flour and then, little by little, the boiling milk.

Pour back into the pan (on a low setting) and stir until the cream thickens. Then let it cool.

When the cream has cooled, you can add a tablespoon of rum, Amaretto or another liquor. You can replace that with almond extract. NB: Do not add anything when the cream is still hot, that would remove most of the taste!

Chocolate version: don't put vanilla with the milk nor alcohol, but add 50 grams of minced chocolate when the cream has thickened and is still hot. Mix well to obtain a homogeneous mixture.

The final touch: the preparation of the choux / eclairs. Fill a piping bag (or a freezer bag with a corner cut off) with cream and fill the choux one by one, making a hole underneath (have you ever noticed the holes underneath the eclairs and religieuses in bakeries?). If you don't have a piping bag, cut each chou / eclair in half to insert the cream.

If you are making gougères (salty versions perfect as an appetiser), add 50g of Emmental or Comte cheese to the dough before forming the choux.