Toast raw sesame seeds (optional): Toasting raw sesame seeds gives the tahini a nuttier flavor. On the stovetop, place the sesame seeds in a dry skillet over medium heat, stirring them frequently with a wooden spoon. Toast the seeds until they are lightly colored (not brown) and fragrant, about 5 minutes. Transfer the toasted sesame seeds to a large plate or tray and let them cool completely. Alternatively, toast the seeds in the oven: Preheat the oven to 350°F. Spread the sesame seeds on a rimmed baking sheet. Toast the seeds, stirring once or twice, until they are lightly colored (not brown) and fragrant, about 5 minutes. Transfer the toasted sesame seeds to a large plate or tray and let them cool completely.