Tahini (טחינה) is the sesame sauce that holds half the Israeli sandwich canon together: raw sesame paste loosened with water, lemon, and garlic into a pourable cream, then spooned, drizzled, or smeared into nearly everything. It is not a sandwich on its own, but it is the load-bearing condiment in falafel, sabich, shawarma, grilled meat, and roasted vegetable builds, so it earns its own treatment. The angle is the sauce as structure. Done right it binds a sandwich, adds richness, and carries acid and bitterness that cut fat; done wrong it makes the whole thing heavy and flat.
The making is short and the proportions are exact. Stirred-up raw tahini paste is whisked with cold water, lemon juice, crushed garlic, and salt, and the trick is that the paste seizes and goes pasty before it loosens, so water is added gradually until it suddenly turns smooth and pale. The target is a sauce that ribbons off a spoon and settles slowly, not a stiff spread and not a thin liquid. In a sandwich it does specific work: in falafel it coats the fritters and glues the salad to the bread, in sabich it pools around the egg and eggplant, in shawarma it laces the meat, and over grilled vegetables it adds the fat the dish otherwise lacks. Good tahini in a sandwich is bright and nutty with a clean bitter edge, applied so it dresses every bite without smothering the thing it is dressing. Bad tahini is gluey and bland from too little lemon and salt, or split and oily, or laid on so thick that a falafel pita tastes only of sesame and the fritter, salad, and pickle underneath all disappear.
It also appears as a feature rather than a binder: a thick swipe of plain tahini with a fried egg, a slick of it under a roasted cauliflower or eggplant sandwich, or a green herb-blended version that doubles as sauce and flavor. It varies first by thickness and seasoning, a looser lemony pour reading sharp and light, a thicker garlicky one reading rich and dense, and second by what gets blended in: parsley and cilantro for a green tahini, amba or s'chug stirred through for heat. Those flavored versions are recognizable preparations of their own and deserve their own treatment rather than a footnote here, but they all return to the same idea: ground sesame loosened with acid and water into a sauce whose job is to bind a sandwich and balance its fat without taking it over.