Freeze ginger overnight.
Remove the ginger from the freezer.
Peel the ginger and cut into 2 cm thick slices.
Add the ginger to a pan and cover (by a couple of centimetres) with water. Bring to the boil, cover and simmer for about an hour and a half to 2 hours until nice and tender.
Drain the tender ginger pieces and reserve the cooking water. Set to one side while you make a syrup.
Measure 600 ml of the ginger cooking liquid and add back to your pan along with the sugar.
Return to a gentle heat and stir to dissolve the sugar – once the sugar has dissolved stop stirring. Bring to a boil and simmer gently for about 15 to 20 minutes until you have a nice thick syrup.
Add the cooked ginger back to the pan and simmer gently for 20 minutes before transferring ginger and syrup into a sterilised jar and sealing. Store in a cool, dry place for up to a year.