Ka'ak b'Labneh (كعك باللبنة) is the sesame street bread filled with labneh, the thick strained yogurt, and the angle is the swap of a tangy spread for a sliced or melting cheese. Labneh is creamy, sour, and salted, with no melt and no chew, so it behaves nothing like the cheese fillings. It coats rather than layers, brings acid where the bread brings sweetness, and asks the build to lean on that contrast: the faintly sweet, nutty sesame crumb against a cool, sharp, fatty smear. It is a breakfast staple, simple and quick, and it stands on the quality of the labneh and on not drowning it.
The construction is about as short as a sandwich gets. The ka'ak is warmed so the crust crisps and the inside softens, then split along its wider end. Labneh is spread generously over the warm crumb, thick enough to stay put but not so thick it overwhelms. A thread of good olive oil goes over it, almost always with a dusting of dried za'atar, which is the classic partner; mint, sliced tomato, cucumber, or olives are common additions. The judgment is in the labneh and the restraint around it. Thin, watery labneh slides out and leaves the bread damp; properly strained labneh holds, stays creamy, and reads as a clean tang against the sesame. Too many add-ins and the labneh stops being the point; too little oil or za'atar and it can read flat, since labneh's sourness wants a little fat and aroma to lift it. A good ka'ak b'labneh is warm and nutty with a cool, thick, gently sour spread brightened by oil and za'atar; a poor one is a runny, bland smear in a stale loaf.
It varies almost entirely by what joins the labneh. Za'atar and oil is the default and arguably the whole point; beyond that, mint, tomato, cucumber, olives, or a little chili push it toward a fuller breakfast spread without changing its character. The labneh itself ranges from mild and soft to sharply tangy and firmly strained, sometimes rolled with herbs. Within the ka'ak family it sits beside the cheese, egg, and za'atar fillings as the strained-yogurt member, distinct because it spreads and sours rather than melting or browning. It is essentially the labneh-and-za'atar breakfast the Lebanese table eats off a plate, picked up instead inside the warm sesame loaf.