Using a very sharp knife, trim the extra fat and the tough silverskin from the beef cheeks. You should have approximately 3 pounds of cleaned meat remaining. Transfer the cheeks to a large nonreactive bowl or casserole and add 2 cups Rioja, 1/2 cup onion, 1/2 cup celery, 1/2 tablespoon garlic, bay leaves, 1 sprig rosemary and the black peppercorns. Stir gently to blend and make sure that the meat is covered by the wine, cover the bowl with plastic wrap and refrigerate overnight or at least 8 hours.

Preheat the oven to 275 degrees F.

In a large, oven proof Dutch oven, heat 1/4 cup oil over high heat until almost smoking. Remove meat from the marinade, pat dry and season on both sides with some of the salt and pepper. Brown the meat in the oil, in batches if necessary, until well browned on all sides. Remove from pan and set aside. Add remaining 1/4 cup oil and add remaining onion, celery and rosemary to the pan along with the carrots. Cook for about 20 minutes, stirring frequently, until vegetables are soft and beginning to caramelize. Add the remaining garlic and cook 2 minutes. Add the tomato paste and cook for another 2 minutes. Strain the marinade and add to the pan along with the remaining red wine. Bring to a boil and reduce by about 1/2. Add the beef broth, Italian Essence, red pepper flakes, pimenton and the herbs. Stir well. Cover tightly and place in the oven. Cook for 3 hours or until the cheeks are very tender. Taste and adjust seasoning, if necessary.