Heat a heavy, wide-bottomed sauté pan over medium-high heat.
Add the sesame seeds and toast lightly for about 2 minutes, shaking the pan so they toast evenly. I tend to just vigorously stir rather than toss. (Keep a careful eye on the sesame seeds as they go from toasted to burnt really quickly. As soon as they start to brown, they are done.)
Transfer to a bowl and let cool completely.
Put the toasted sesame seeds in a food processor and drizzle in the olive oil.
Pulse for 3-5 minutes, or until it's as smooth as you can get it.
Add a little more olive oil if necessary.
Remove from food processor and store in the refrigerator.
Notes
Yields about 2 cups.Tahini should be stored in the refrigerator if not used within a few days.