Tahini is a nutritional powerhouse, containing many B vitamins, as well as being a source of Vitamin A, and is high in calcium. It also contains potassium, magnesium, iron and phosphorous, and is a richer protein source than milk, soya beans, sunflower seeds, and most nuts.
I used to make my own hummous very regularly - it is dead easy if you have a blender, Magimix, or similar food-processing gadget - but some years ago, I discovered Yarden Hummous Extra, the smoothest hummous I've ever eaten, dressed with olive oil and toasted pinenuts. I have tried to recreate the texture of Yarden Hummous, but even lengthy pureeing in my Magimix cannot quite achieve its creamy smoothness. You can buy it in Waitrose and Kosher delicatessens.
For me, Tahini is associated with the summer, as I make a barbecue marinade for chicken with Tahini and smoked paprika (from the Moro Cookbook). Find the recipe here. It works equally well with other joints of chicken, and doesn't have to be barbecued, either!
Tahini is also an essential ingredient of Baba Ghanoush, that delicious Mediterranean dip made from char-grilled aubergine. The nuttiness of the Tahini compliments the sweetness of the aubergine. Here's a nice, authentic, and very easy recipe from Nigel Slater.
Yotam Ottolenghi, founder of the epoynmous deli and cafe chain, includes many recipes using Tahini in his oeuvre - unsurprising since he comes from Israel, where it is used in a huge variety of dishes, both sweet and savoury. A couple of his most interesting recipes below:
Fried cauliflower with tahini
Mushrooms with walnut and tahini yoghurt
More on Ottolenghi here