• Preheat the oven to 200˚C fan / 220˚C / 392˚F convection / 428˚F.
• Line two baking trays with baking paper.
• In a medium saucepan, heat the water and butter until the butter has melted and it just begins to boil.
• Take off the heat, add the flour all at once, and then return to a medium heat and beat for 1-2 minutes with a spoon until the mixture is smooth and comes away from the sides of the pan.
• Take off the heat and leave to cool slightly in the pan - around 5 minutes.
• Beat in the eggs a little at a time with an electric whisk until the mixture is thick and glossy. (Once the eggs are incorporated, it is easier to use a spoon to get into the corners of the pan).
• Place teaspoons of mixture onto the trays, leaving a gap of 3-4 cm (1.2 - 1.6") as they will rise slightly.
• Dip a finger into a little water, and use it to gently tidy any points or ribbons of mixture (these can catch and burn in the oven before the profiteroles are ready).
• Place in the oven and bake for 10 minutes, then reduce the heat to 180˚C fan / 200˚C / 356˚F convection / 392˚F and bake for another 15 minutes, until the profiteroles are golden and firm.
• Leave on the tray for 5 minutes, then transfer to a wire rack. Make a small hole in the side of each profiterole to let the steam out. Leave to cool completely.
• When completely cold, fill the profiteroles.

To fill the profiteroles:

• Whisk the cream cheese with the horseradish (if using) and season with black pepper.
• Slice the smoked salmon into 4-5cm (1.6 - 2") thick slices.
• Tear off small fronds of dill, if using.
• Carefully slice the profiteroles across the side and then fill with a teaspoon of the cream cheese, fold a slice of smoked salmon and place on top of the cream cheese, and add a small frond of dill, if using.
• Place on your serving dish and serve straight away.