Add the remaining 2 tablespoons of oil and the onion to the pot. Cook over moderate heat until softened, about 5 minutes. Add the garlic, chile powder, cumin, oregano and chipotle powder and cook, stirring, until fragrant, about 2 minutes. Return the turkey to the pot. Stir in the carrot, bell pepper, tomato puree, beans and lager and bring to a boil. Stir in the stock and vinegar, cover and simmer over low heat for 45 minutes. Add the thyme, season with salt and pepper and serve, garnished with chives.