I assume black tahini is just sesame paste from black sesame? If so, take cues from Asian cookbooks. You could use it in sauces for vegetables or noodle dishes. I particularly like black sesame on cruciferous veggies or green beans, mixed with a little shoyu, vinegar, and sugar, or maybe some miso thinned with mirin. You could also probably make some pretty heinous desserts. I've been searching for black sesame ice cream ever since I heard it's available on the west coast, no luck yet. I'm dreaming of a recipe using your black tahini...