Upstairs on the Square is the reincarnation of a longtime Harvard Square favorite, Upstairs at the Pudding. It opened in its new location in late 2002 and immediately reestablished itself as the kind of restaurant that puts the "special" in "special occasion." The Soiree Room, atop the four-story building, is the place for that big anniversary dinner: It's a jewel box of pinks and golds under a low, mirrored ceiling. The menu is enjoyably old-fashioned, with straightforward main courses (a slab of swordfish, a generous rack of lamb) that contrast with bolder starters (luscious Jerusalem artichoke or watercress soup, a simple but superb haricots verts [green beans] salad). Downstairs, the second-floor Monday Club Bar dining room is a casual yet romantic space where firelight flickers on jewel-toned walls. The food -- salads, sandwiches (including a daily grilled-cheese option), fried chicken, steak with baked potato and onion rings -- is homey and satisfying. In both rooms, you'll find outstanding wine selections and desserts.