Where can you find tahini? I usually find it in asian markets, whole foods, other natural food stores and any middle eastern markets.
Here is a recipe:
http://mideastfood.about.com/od/appe...usbitahini.htm
I usually omit olive oil because I think tahini is a bigger flavor add than olive oil. I've heard some people omit tahini and add olive oil. If you wanted to do that, Trader Joe's carries an awesome kalamata olive oil that would probably be great but I still prefer tahini/no olive oil.