Sift flour on to a sheet of greaseproof paper. Place the water and butter in a small pan and heat gently until the butter melts. Bring to the boil and immediately add the flour. Beat rapidly over the heat for about 1 minute until smooth.

Remove from the heat and beat for about 5 minutes until cooled. Gradually beat in just enough egg to form a smooth, glossy, stiff paste.

Using a large piping bag and 1/2 inch (1 cm) plain or star nozzle, pipe the choux pastry into 3 inch (7.5 cm) fingers on to a greased baking tray.

Bake for 20 to 30 minutes at Mark 7 (220°C) 425°F until brown and very crisp. Cool on a wire rack.

Split. Dip the tops of the buns in melted chocolate or glace icing and fill bases with whipped cream or creme patissiere. Sandwich together.