Meanwhile, in a large, deep skillet, heat 3 tablespoons of the olive oil. Season the chicken with salt and pepper, add it to the skillet and cook over moderately high heat until lightly browned, about 4 minutes. Add the onion and garlic and cook over moderate heat until the onion is softened and the chicken is cooked through, about 4 minutes. Add the diced tomatoes, chipotle and adobo sauce and cook until heated through, about 2 minutes. Add the corn, season with salt and pepper and cook until the corn is heated through, about 1 minute.