Hmm... may as well jump in, and thanks again for the plug VN... Farmers' markets, easy to find - mostly small neighborhood ones, but there are four large ones that operate - San Telmo (behind Plaza Dorrego), Belgrano (Juramento & Ciudad de la Paz), Recoleta/Centro (Callao & Cordoba), and the biggie, Mercado del Progreso at roughly Rivadavia 5200 in Caballito.Sour cream, used to be available, not anymore that I know of. Easy to make a good substitute - take one of those 350ml things of heavy cream, mix in the juice of a lemon and a teaspoon of salt, let it sit out at room temp for about 3-4 hours, stirring occasionally.Smoked ham - the Valenti chain usually has is, sometimes you can find it at other little markets that specialize in cured meats as well."Real Gruyere" - probably not. But if you go to a decent cheese shop, you can find good versions of the domestic, rather than what you see in the supermarkets.Rhubarb - grown in Patagonia, and it occasionally pops up in the markets listed above around the late summer - so maybe in February - but really limited quantities. There's a place called Diki, at Libertad 1157, that sometimes has jars of rhubarb puree from Patagonia that isn't overly sweetened, but it's not count-on-able...There's no question that ingredients, especially things that aren't grown or produced domestically, are hard(er) to find here and/or are often very expensive (that 50% import tax is a killer), and if you aren't interested in spending time looking, you probably won't find them. But hey, it's one of the tradeoffs of living here. There is, however, lots of very interesting domestic cuisine, that goes far beyond pasta with tomato sauce and milanesas with french fries - and while those may be ubiquitous in neighborhood cafes, my experiences at people's homes suggests that "the typical housewife" cooks far more adventurously than that.
