Preheat the oven to 200 degrees Celsius (392 degrees Fahrenheit) fan.

Bring water and butter to a boil. When the butter and water are boiling, add the flour and stir quickly. When the mixture pulls away from the sides of the pot, remove it from heat.

Let the dough cool slightly (if the dough is too hot when the eggs are whisked in, the eggs and dough will not combine properly).

Once the dough has cooled a bit, whisk in the eggs one at a time (you may use a hand mixer if desired).

Once all the eggs are whisked in and the dough has come together, place it in a piping bag fitted with a star nozzle. Pipe the dough onto a baking sheet lined with parchment paper in heart shapes.

Bake the choux pastries at 200 degrees Celsius (392 degrees Fahrenheit) fan for 15-25 minutes. Avoid opening the oven before 15 minutes have passed, as the choux pastries will collapse.

Let the choux pastries cool on a cooling rack before filling them.