Thanks for the info. I found the chinese restaurants in Rep Francesa, and they are what I was after.
I also found 2 chinese supermarkets in Mercado 4. One was in Rep Colombia, about a 1/2 block from Peru, and the other was in Peru, between Francia and Ana Diaz. Both sold Sesame Oil, Oyster sauce and other ingredients, but not Chinese 5 spice or fish sauce. I went to Shopping Villa Mora to the Agromarket and there was one stall selling chinese ingredients, inc oyster sauce and sesame oil, again no chinese 5 spice or fish sauce.
I looked up the internet for a 5 spice recipe, bought the ingredients at a herb shop in Mercardo 4, and made it myself using a coffee grinder.