I'll be staying in Union Square with my 2 nieces (ages 7 and 8) right before Xmas for one night, and wanted to treat them to a fun, casual meal after ice skating at Embarcadero. We will be going to tea (Fairmont or Ritz) beforehand, and they will be tired, so I don't want to take them anywhere too fancy, but festive would be great. Does anyone have any ideas for a good place I could take them, that maybe is festively decorated, but serves burgers or other kid-friendly food? I thought maybe of Kells, since the decorations look so cozy, but I have never eaten there. Other ideas? A short cab ride is no problem.