This robust chili has sweetness from the corn and cinnamon, spice from the chiles, and a depth of flavor from the cocoa. The short ribs fall apart with a fork and add extra body to the chili (just make sure to trim them well before you start cooking).
Heat 1 tablespoon of oil in a large, heavy pot (or Dutch oven) over medium-high heat. Add the short ribs to the pot and sear the meat on all sides then set aside. Sauté the onions and garlic with the remaining ½ tablespoon of oil over medium heat until they are soft and translucent. Add the spices and cocoa to the pot and cook for 1 minute before swirling in the tomato paste. Return the short ribs to the pot, along with the beans, corn, chiles, and beer. Cover and reduce the heat to low and simmer until the meat is tender — about and hour and a half.
Ladle into bowls and garnish with the cheese and sour cream.