After you cross Dr. Delgado and are just above "Little China". There is a big sign outdoors.
As for the 'wasabe' yellow mustard sauce that is basically dried horshradish and water, I have never even seen it except at a japanese friend's place in Santiago.
You might ask for "Picante" but that will be red hot sauce.
You can find this at Chinese places in the States and bring it with you...ie. the dried preparation....

I agree on the Plaza at naco, too.. Neat place, but if these guys are on an $85/day budget??

HB