The day before, put the soft butter into a mixing bowl and cream it with the flat side of a rubber spatula. Add the sugar and salt to the butter and mix well, then add the egg yolk and continue mixing until everything is well combined. Add the rice flour and mix again until the flour and butter mixture are also well combined. It will look crumbly when ready.

Knead the crumbly dough with your knuckles until it comes together and forms a cohesive dough. Once your doughy mixture is ready, sprinkle in the chocolate chips and knead the dough once more.

Divide the dough into two and shape each piece into a log. Wrap each log in cling film (plastic wrap).

Ideally, pop the wrapped dough logs into the fridge overnight. Alternatively, put them into the freezer for about 40 minutes. Put the baking sheet into the fridge, too, so it is also chilled.

Preheat the oven to 170 degrees Celsius (340 degrees Fahrenheit). Once chilled, take out the dough and cut it into discs about 8-mm to 1-cm (1/2-inch) wide.

If the cookies have lost their shape, use your fingers to press them back into rough round shapes. Place the discs on a baking tray.

Pop them straight from chilled into the preheated oven and bake for 18–20 minutes. Enjoy the cookies while still warm with gooey chocolate chips!