smoked sulguni
Georgian stretched-curd cheese made from cow's or buffalo milk, brined and then smoked, sliceable, stringy and elastic, salty with a distinct smoky note.
Sulguni is a Georgian cheese made by the pasta filata method: the curd is kneaded and stretched in hot water, shaped and placed in brine. The smoked version has a golden to dark brown rind and a firmer, drier interior than fresh sulguni. It tastes distinctly salty, milky and smoky and pulls apart into strands and layers. When heated it melts into stretchy strings without releasing much fat, which suits it to grilling, frying and baking as well as slicing cold. It is sold in Russian and Eastern European grocery shops, sometimes in Caucasian or Turkish supermarkets, and by mail order.
Substitute:
Smoked scamorza comes closest, being likewise a smoked stretched-curd cheese that melts and strings in a similar way; it is milder and less salty, so add a little more salt or mix in some feta. Smoked mozzarella also works but is softer and wetter.