I buy a jar of Tahini and take out a couple of tablspoons with a normal whisk or hand held blender which puts more air into it of course, I add garlic and some salt or tamari to taste, some water and olive oil, you could put lemon juice in it too, as you whisk it gets lovely and smooth, though it starts off a bit lumpy (it's a flexible recipe of course).
They sell it ready made of course but it's much cheaper to make your own!