Lightly toast the sesame seeds. Add the sesame seeds to a large sauté pan. Cook over medium heat, stirring frequently, until they are very very lightly toasted. (We mainly want to heat the seeds and avoid them turning golden; they should only have the slightest bit of toasted color.)

Blend. Immediately transfer the hot seeds and salt to a high-powered blender or food processor. Blend for 1 to 2 minutes, pausing to scrape down the sides as needed, until the seeds form a coarse powder. Stream in 3 tablespoons of the oil and continue blending for 2 to 4 more minutes, pausing to scrape down the sides as needed, until the consistency is smooth and pourable. If the mixture seems too thick, add in more oil as needed.

Serve. Serve the tahini immediately or refrigerate in a sealed container for up to 1 month.