Bring a large pot of lightly salted water to a boil, and cook the vermicelli pasta 4 to 6 minutes, or until al dente. Drain, rinse with cold water, and let cool for about 10 minutes.
In a large bowl, mix the tahini, olive oil, mayonnaise, lemon juice, water, garlic, and sugar. Season with cayenne pepper, garlic salt, onion salt, and chives.
Transfer the cooled vermicelli to the bowl, and toss with the tahini mixture to coat. Chill until serving.