1. Place milk, cream, 1/4 cup sugar, ginger, and ginger root in a small pan and cook over low heat, whisking now and then, until warm (175F). Set aside for 1 hour, then strain out the solids. Keep 2 tsp of the ginger root.
  2. Whisk egg yolks, 1/4 cup sugar, vanilla extract and salt in a small metal bowl until combined. Temper with the milk mixture, then add to the saucepan and cook until thickened, about 185F. Do not boil. Strain out the solids.
  3. Cool for 3 hours.
  4. Add reserved ginger root back in. Prepare in ice cream maker. Add candied ginger in the last 5 minutes of processing.

source: Ice Cream by Sally Sampson