Also, I changed 2 things. I used fozen corn instead of peas, because i already had those. And I used normal white potatoes because I dont think ive ever seen Blue potatoes in chicago, or the U.S for that matter. Peru, yes, and they are delicious!
Heres how to make the paste: http://canelaycomino.blogspot.com/2008/02/diy-aji-amarillo-paste.html
And here is the recipe from Martha Stewarts website: http://www.marthastewart.com/recipe/peruvian-sudado-de-pescado