Grate the ginger, and combine with the sugar and water in a heavy-bottomed saucepan over medium heat, stirring occasionally – about five minutes.

As the ginger/sugar mixture is heating, add the egg yolks to a large bowl and whisk to combine.

Add 2 cups of the half and half to the saucepan, lower to medium-low, and heat till simmering but do not boil – this will take about ten minutes (better to go slow and not risk boiling). Make sure to stir occasionally, including scraping the sides of the saucepan.

Add the hot mixture from the saucepan to the large bowl with the yolks in a slow stream, whisking constantly.

Transfer the mixture back into the saucepan over low, and heat until the mixture thickens over the back of a spoon (about 170 degrees) – this will only take a few minutes.

While the mixture is reheating in the saucepan, rinse out the bowl (or….don’t) and add the remaining half and half and vanilla extract to the bowl, setting a sieve over it. When the custard is properly heated, pour it through the sieve into the bowl, pressing out all liquid from the ginger solids, stirring to combine.

Chill the mixture in the fridge until completely cool (at least three hours), then churn in your ice cream maker according to its instructions.

While the mixture is chilling in the fridge, you can finely chop the candied ginger (if using) – adding this to the ice cream maker when it’s about 75% of the way through churning.