1. Grind tahini paste, lukewarm water, garlic, lemon juice and salt together in a food processor or blender until sauce is creamy and ivory-colored. A food processor is the easiest way to make this sauce; scrape the sides of the processor periodically during processing. If using a blender, you may need to use a long-handled spoon to break up the thick part of the sauce once every 30 seconds; this will keep it from clogging your blender blades. 2. After a few minutes of blending, sauce will turn into a rich, smooth paste. If mixture is too thick, slowly add more water until it reaches the preferred consistency. You may need quite a bit of water depending on the thickness of your tahini paste. 3. If using tahini to top hummus or a meat dish, keep it thick and creamy. As a condiment for pita or falafel, a more liquid sauce is usually preferred. Taste often during the blending process; add more lemon juice or salt, if desired.