Cook the potatoes and blend to a purée. Mix with the mustard, base and water at room temperature.
Place the mixture into the batch freezer. Remove the gelato from the batch freezer when it reaches appro -4/-5°C.
Presentation
Make the beef tartare and the pear cubes. Season with salt and olive oil.
Serve the dish as in the photo by garnishing with the mustard gelato and pear chips.