My friends who live across the street and I refer to this as "No Pride Superette": once a year or so one of us is too lazy to walk a block to Mama's at 22nd and Dolores or Mama's is closed so we sneak in here, buy something, take it home, discover it's well past its expiration date, we're appropriately mocked and ashamed, and we vow never to go in again.
RUN AWAY. This place was bad enough to finally get me to post my first ever Yelp review. Sort of a community service.
There are some restaurants in San Francisco that probably do steady business no matter what their food is like. Cathay House is the perfect example. It's what you'd have to call a "tourist trap". You're in San Francisco for a day or two, wandering down Grant through Chinatown and you think "Hey, this place looks good, let's grab lunch. It looks like the Hunan House back in [insert city name], [insert midwestern state], but it's in Chinatown... so it must be good." It is not. They have a steady stream of unknowing foot traffic. Lambs to the slaughter, so to speak. We should've known better, as in-towners, but we got lazy and let our guard down.
The first, glaring warning sign should have been the fact they asked "Would anybody like *chopsticks*?", then pointing out that the instructions were on the paper wrapper.
The odd crumb encrusted things the size of a microwave burrito might have been a pretty good eggroll, if not for the fact that it was burned, but did bookend the meal nicely with the burned fortune cookie. The little perfect cubes of chicken in the chicken fried rice were indistinguishable from erasers, and the rice itself was likely cooked at least 6 hrs before we got there. Cathay seems to subscribe to the philosophy that you can just throw the most freezer burned pork in a blaze orange sweet and source sauce or cover the fattiest cut of beef you can find in a thick brown reduction of soy sauce and cornstarch and nobody will notice. They're wrong.
Stay away. Walk one block away from Grant in either direction and just pick anywhere. 90% chance it'll be better.