I feel your pain! On my big trip to many countries, I always looked for Mexican food at every city that I stayed in. I also brought my own hot sauce with me. In Asia, I had a lot of nights when I only ate potato chips for dinner because the food in restaurants didn't look very good.

It's good to try new things, but I don't want every meal to be a "cultural experience". Sometimes I just want to eat the food that I know and love.

I don't know if Peru has many Asian grocery stores, but you may be able to ask at Asian restaurants where they buy their ingredients. Then maybe you can buy some fish sauce to bring with you. At the very least, you should be able to find some soy sauce (I know, it's not the same).

You can also ask around at places where a lot of expat westerners hang out. It may be easier to communicate in English, and lots of westerners like to cook food from around the world. They should be able to point you toward some fish sauce. This thread has a little information about finding fish sauce in Peru, but it looks like most stores are in Lima :(

The pasta dish that you made looks delicious!