What is Mast-o-Musir?

Mast-o-musir is thick yogurt beaten smooth with musir, the wild shallot that grows in the Zagros mountains and is sold dried, sliced into what look like pale wood chips. The slices have to be soaked, usually for a full day with the water changed two or three times, until they soften and shed their most aggressive edge; then they are minced or crushed and folded into strained yogurt with salt. Left overnight in the fridge, the mixture stops being yogurt-with-bits-in-it and becomes its own thing: tangy, faintly sweet, with a garlicky bite that arrives at the back of the throat a second after the spoon leaves your mouth. It is the standard opener at kababi restaurants across Iran and the diaspora, scooped up with warm sangak or lavash while the koobideh is still over the coals, and it is also the correct thing to spoon directly onto a plate of rice and grilled meat.

Musir is not garlic and it is not a French shallot — it is Allium stipitatum, foraged rather than farmed, and traditionally preserved by slicing and drying, which is why it turns up looking like something you would use to start a fire. Some cooks soak it in vinegar or in yogurt whey instead of water, which mellows it in a different direction. The soaking time is a genuine household argument: too short and it stays harsh and crunchy, too long and the whole thing goes flat. Ready-made tubs sit in the cold case of every Iranian grocery from Westwood to North Vancouver, and they are consistently, noticeably weaker than homemade — which is precisely why people keep making it. Some families add nothing else at all; others scatter dried mint or pour a little oil over the top, and a purist will tell you that is already one step too far.