Season the meat generously with salt and pepper. Heat 2 tablespoons of the oil in a large soup pot over medium-high heat. Brown the beef for about 4 minutes, or until it is seared on all sides, then remove it from the pot.
Heat the remaining 1 tablespoon of oil in the pot over medium heat and sauté the carrot and onion for about 10 minutes, or until the onion turns slightly translucent. Add the water, beer, soy sauce, and beef to the pot. Bring to a boil, then decrease the heat and simmer gently, covered, for 1 1/2 hours.
Add the tomatoes with their juice, the barley, butter, and mushrooms to the pot and cook for an additional 30 minutes, or until the barley is tender.
Season with salt to taste and stir in the cilantro just before serving.