* Tahini is ground sesame seeds. It's used in most hummus recipes and you can find it in the Middle Eastern section of larger grocers or at any Middle Easter grocery. You can also order Tahini online.
** ~ If you make your own hummus you may have noticed that it can have a somewhat bitter taste. I learned something interesting recently from Cook's Illustrated; extra-virgin olive oil should never be put in a food processor - and this is what they say about it; extra-virgin olive oil contains bitter-tasting compounds called polyphenols that are normally coated by fatty acids, which prevent them from dispersing in the presence of liquid. When olive oil is broken into droplets in an emulsion, the polyphenols get squeezed out and will disperse in any liquid in the mix, so that their flavor becomes evident. The blades of a food processor break olive oil into much smaller droplets than those created from whisking. The smaller the droplets, the more polyphenols that break free and disperse, and the more bitter an emulsion will taste. (Note: In recipes such as pesto, which contain lots of other robust flavors from herbs, nuts, and cheese, we found that any bitter taste went unnoticed.) That's why I recommend adding the olive oil after removing the hummus from the food processor. I agree with Cook's Illustrated, I think it really does make a difference!
** ~ I know, I know this sounds like a ton of cilantro - it is! But this is what gives it such a bright, fresh flavor. And combined with the other ingredients, it doesn't taste too "cilantro-y", even if your not that fond of cilantro on it's own, I think you will love this!