Steam the taro cubes until very soft, about 15-20 minutes.
Let cool slightly.Puree the steamed taro in a food processor or blender until smooth.
In a medium saucepan, combine the cream, milk, and sugar. Heat over medium heat, stirring until sugar dissolves .
In a separate bowl, whisk the egg yolks. Slowly pour about 1 cup of the hot cream mixture into the egg yolks, whisking constantly to temper the eggs.
Pour the egg mixture back into the saucepan with the remaining cream mixture, stirring constantly. Cook over medium-low heat, stirring continuously, until the mixture thickens enough to coat the back of a spoon (about 170°F/77°C).
Remove from heat and stir in the pureed taro, salt, and vanilla extract. Add food coloring if desired.Strain the mixture through a fine-mesh sieve into a bowl.
Cover and refrigerate until completely chilled, at least 4 hours or overnight. Churn the chilled mixture in an ice cream maker according to manufacturer's instructions.
Transfer to a freezer-safe container and freeze for at least 2 hours before serving.
