Use an aluminum ginger grater or a rasp grater such as a Microplane to grate ginger. Press the grated ginger through a fine strainer using the back of a spoon to press out as much juice as possible. 

Place the ice cream in a medium bowl and fold in the ginger juice. Cover the mixture tightly with plastic wrap and refreeze the ice cream until firm, at least 30 minutes.

Serve with a slice of candied ginger.