Preheat oven to 220°C/200°C fan-forced. Grease a large baking tray. Line with baking paper.
Place potato in a saucepan. Cover with cold water. Bring to the boil. Boil for 15 minutes or until tender. Drain. Transfer to a bowl. Mash. Using a large metal spoon, press potato through a fine sieve into a bowl. Add egg yolk and half the butter. Season with salt and pepper. Stir to combine.
Spoon mixture into a piping bag fitted with a 2cm fluted nozzle. Pipe sixteen 3cm rosettes onto prepared tray.
Drizzle remaining butter over potato. Bake for 20 to 25 minutes or until lightly browned. Serve.
Serving size: 6
Recipe courtesy of taste.com.au