Gougères with Brugge Old

Pre-heat the oven to 200 °C (convection).
Heat water, milk, salt and butter on low heat until the butter has melted and the liquid almost boils.
Add the flour in one go and stir until you get a homogeneous dough ball which easily comes loose from the bottom.
Take off the heat, pour the dough into a mixing bowl and stir in the Brugge Old.
Now stir in the eggs one by one. Do not add a new egg until the previous one has been fully absorbed.
Finally, stir in mustard, chives and pepper.
Pour the dough into a piping bag and put small piles on a baking tray covered with baking paper. Wet your index finger and flatten the tips.
Slide the baking tray into the oven and bake the gougères for +/- 15 minutes until golden brown.
Leave to cool slightly and serve.
If you want to make the choux in advance, put them in the oven just before serving for 2 to 3 minutes to warm up.