Grab your stick blender and puree until smooth. Using a set of scales weigh how much puree you have then place puree back into the saucepan. Measure out the same amount of sugar and add to the puree. Add ginger and lemon juice. Heat over medium heat and stir until sugar has dissolved. Boil away for 20 to 25 minutes until puree becomes thick like a syrup. Remove from heat immediately. Test by spooning a small amount into a chilled cup and if ready it should firm up to like a paste. Let cool for 5 minutes and take out your ginger slices. Be sure not to leave unattended while boiling. The paste is like a toffee and can go from being ok to be burnt really quickly in a split second.