Thanks. I agree. Although considered a seed rather than a nut, sesame does have most of the characteristics of nuts. Those with nut allergies must avoid them. In the absence of Tahini I would add a little peanut butter and also a tad of sesame oil, widely available due to its use in Chinese cooking. If feeling adventurous one could blend some sesame seeds with sesame oil to create one's own form of Tahini.
As you can see from above, and countless sources on the internet, peanut butter is a perfectly adequate substitute for Tahini.
Anyway, like I said to the other guy, care to post your recipe or are you just going to criticise?