Greek food is not easy to come by in San Francisco, but at this sweeping, comfortable restaurant, complete with a roaring fireplace where everything from lamb to suckling pig is spit-roasted, you can feast like Zeus.  Chef Erik Cosselmon does the expected Greek classics beautifully, but the more adventurous diner can enjoy the likes of goat stew, grilled octopus, whole fish and house-made headcheese.