Instructions: Toast the black sesame seeds in a dry skillet over medium heat until fragrant, about 5 minutes. Let cool. In a blender or food processor, grind the toasted sesame seeds until they form a fine powder. In a saucepan, combine the ground sesame seeds, heavy cream, and milk. Heat over medium heat until it begins to simmer, then remove from heat. In a separate bowl, whisk together the sugar and egg yolks until pale and thick. Slowly pour the hot sesame mixture into the egg mixture, whisking constantly to prevent curdling. Return the mixture to the saucepan and cook over medium heat, stirring constantly, until it thickens enough to coat the back of a spoon, about 5-7 minutes. Do not let it boil. Strain the mixture through a fine mesh sieve into a clean bowl to remove any lumps. Cover and refrigerate until completely chilled, preferably overnight. Churn the chilled mixture in an ice cream maker according to the manufacturer's instructions. Transfer the churned ice cream to a container and freeze for at least 4 hours before serving.