Preheat a large skillet over medium heat. Add the sesame seeds and toast them, stirring frequently, until they are golden brown and fragrant (about 5-7 minutes). Be careful not to burn them. Transfer the seeds to a plate and let them cool completely.

Once the seeds are cooled, transfer them to a food processor or high-speed blender. Blend the seeds until they form a crumbly paste.

With the food processor running, slowly add the oil one tablespoon at a time until the mixture becomes smooth and creamy. You may need to stop and scrape down the sides of the bowl occasionally. The amount of oil can be adjusted to achieve your desired consistency.

Add a pinch of salt if desired, and blend once more to combine. Transfer the tahini to a clean, airtight jar and store it in the refrigerator for up to a month.