Combine turbinado or light brown sugar, egg yolks, and salt in a 3-quart stainless steel saucier, then whisk in cream and milk. Cook over medium-low heat until warm to the touch, then increase to medium and cook, stirring constantly with a flexible spatula, until mixture is steaming-hot but not bubbling, about 8 minutes or to 155 degrees F on a digital thermometer. Off heat, whisk in black sesame paste and strain mixture through a fine-mesh sieve into a large stainless steel bowl. For a more homogeneous color, process about 30 seconds with an immersion blender; this is strictly an aesthetic consideration.
