Season the pork cubes with salt, pepper, and paprika. Dredge in the flour. Heat a Dutch oven with 3 tablespoons vegetable oil, 3 turns of the pan, over high heat. Brown the pork on all sides. Remove to a plate, reduce the heat, and add the remaining 1 tablespoon of oil. Add the onions, peppers, celery, and garlic and season with salt and pepper. Cover and sweat for 8 minutes or so. Uncover and stir for 1 to 2 minutes, and then deglaze the pot with the beer and let the liquid reduce, 1 minute more. Add the tomatoes, chipotle and adobo sauce, thyme, and cilantro and heat through. Add the pork back to the pot and simmer over medium-low heat until ready to serve. Char the tortillas or prepare quick-cooking polenta. Serve with lime wedges for topping.