Pour the oil into a dutch oven or large, deep, oven-safe skillet or pot and bring to medium heat. Add the green pepper, onion and garlic and stir to coat. Cook for 6-7 minutes, stirring occasionally, until the vegetables are softened. Add in the chilies, chili powder, cocoa powder, cumin, cinnamon, sugar and salt and stir to combine. Add the ground beef and stir to coat. Cook, breaking up the meat with a spoon until browned, about 8 minutes.