If you sit down at any neighborhood joint in Colombia for a bite, you will see small bowls filled with something that looks like a watery relish. This is ají, and it is delicious and not at all relishy. Ají is vinegary and salty and a bit spicy, and it is served with all manners of Colombian food, but especially with empanadas, papas rellenas and other fritanga, as it is a perfect complement to heavier fried foods. Along with hogao, the tomato and onion base used for much of Colombian food, ají is one of the defining sauces in Colombian cuisine.