Ajiaco is a unique Colombian dish, especially beloved in the city of Bogotá. It's a hearty chicken soup made with potatoes and corn on the cob. Small yellow Andean potatoes called papas criollas are the important ingredient - they dissolve and thicken the soup as it cooks. Ajiaco is seasoned with a Colombian herb called guascas, which is apparently a plant known as "Gallant Soldier" in North America, where it is considered an invasive weed! Ajiaco traditionally served with slices of avocado, capers, and a mild sour cream.
You can usually find frozen papas criollas as well as dried guascas at Latin food markets - they are worth seeking out if you decide to make this dish. I couldn't find dried guascas at the store, but I'm going to check my yard (home to many invasive weeds). If you would like to try ajiaco but don't have time to search out the specialized ingredients, try this recipe. If you have access to papas criollas and/or guascas, try this very authentic recipe from andreasrecipes.