1. In a small saucepan, bring the water, milk and butter to the boil.

2. When boiling add the flour and immediately mix vigorously. Turn the heat down to low and continue beating until it forms one smooth ball of dough.

3. Let it cool for a few moments until just warm.

4. Beat the eggs in a small bowl until well mixed. Add the egg to the mixture a little at a time, beating the mixture until smooth each time with a wooded spatula. You may not need all the egg – just check the consistency, when the mixture drops off the spatula easily it is ready.

5. Add the Gruyere cheese and mix lightly.

6. Spoon the mixture into a piping bag and pipe out onto greaseproof paper. Pipe into 1-inch mounds (the mixture makes about 20-25).

7. Brush a little of the beaten egg over the top if left over or use milk. Press down with the pastry brush slightly so that the top of the mound is smooth.

8. Sprinkle the Parmesan over the Gougères. While holding onto the baking sheet and greaseproof paper gently shake the excess Parmesan off so that it doesn’t burn during cooking.

9. Cook in the oven for 15-20 minutes until golden brown, turning after 5-10 minutes.

10. Place onto cooling rack as soon as they come out of the oven.