Replying late (having just shown Himself the joys of McMoogles) to say the following:
1) Nesa informs me the del Solian food you get from Cactuar Hut is cut-rate, and nowhere near as good as the stuff you'll get from even a vaguely decent del Solian delicatessen in the suburbs below the Plate. 2) Cactuar Hut actually does better on their Cosmo Canyon cuisine - their nachos are to die for, and they do the guacamole just right. But don't order the enchiladas unless you know and enjoy your spicy food. 3) The best Gongagan food in Midgar is done by a small deli on the corner of Twelfth and Vine in sector three Topside, but they only do takeaway alternate Thursdays, the same day the trooper's canteen does Mideel-style apple pie, so Zack's never yet been able to get Cloud over there to try the stuff. 4) There is one place which serves Nibel-style food. It moves around a bit, because the main characteristics of Nibel cuisine are either "white sauce with everything" or "boiled with mint sauce" and it's very hard to sell that when you're competing with a Wutai noodle bar, two different places selling burgers, another place serving what they claim to be genuine del Solian paella with chips, and a bloke carrying a tray of sausages-on-a-bun with mustard and onions. The owners keep going out of business, finding a new source of capital, and setting up again in the hope that this time they've found their market. 5) The upper classes of Midgar will tend to employ chefs from Junon, if only for the swank value. There's a nice little night school in sector two below the Plate which teaches cooks from all over the world how to speak with a convincing Junon accent. This is apparently successful, since at least two of President Shinra's exclusive chefs look to be more Wutain than Tseng, yet speak their Midgarian with a Junon accent which could be sliced and buttered.