Process the semi-frozen beef in the food processor until minced, then add the ice cubes.

Keep processing until the mixture clumps into a ball shape, about 2-3 minutes.

Add the salt and process for 1 minute.

Add the mushroom broth powder and process for 1 minute.

Add the egg white and process for 1 minute, then turn off the processor and clean the mixture stuck around the sides of the jug.

Add the tapioca flour and process for 1 minute.

Clean the flour stuck to the sides of the jug again, then process briefly once more.

Remove the mixture and transfer it to another container.

Beat the mixture with a spatula or the palm of your hand to release the air trapped inside.

Shape the mixture into balls and drop them into a pot of water that was previously boiled and then had the heat turned off.

Boil the meatballs until cooked, stirring occasionally so the water does not come to a full boil while they poach.

Take one meatball and cut it open in the middle to check that the meat is fully cooked through.

Once cooked, remove the meatballs immediately and drain them.

Place them in a container, let the steam escape, then cover.