Variations on traditional oxtail soup include adding different ingredients, such as mushrooms, and making the recipe Hawaiian style. Another variation is cooking the traditional soup in a slow cooker.
Traditional oxtail soup calls for trimming the fat from roughly 2 pounds of oxtail in 3-inch segments and then browning them in oil. Cooks simmer this browned meat for three hours in beef stock, wine and tomato puree with vegetables such as onion, celery and carrots. Standard flavorings are salt, pepper, bay leaves and thyme.
To cook oxtail soup in the slow cooker, first rub salt all over the oxtail segments and refrigerate for two hours. Rinse the salt away, and brown the oxtail segments in oil. Layer the meat with herbs such as tarragon, rosemary, thyme and oregano in the slow cooker.
Add 2 cups beef broth to the slow cooker and enough red wine to cover the meat. Stir to combine, and cook on the low heat setting for eight hours.
The Food Network offers a recipe that calls for preparing the standard soup as directed above. Next, add 8 ounces button mushrooms to the soup, and cook for 30 more minutes. Serve this dish over buttered egg noodles flavored with minced shallots and garlic.
Hawaiian oxtail soup is cooked basically the same way but with different ingredients. Omit the vegetables and add instead 1/2 cup raw peanuts and 2 cups mustard greens. Flavor with dried orange peel, star anise, fresh ginger and chili pepper flakes. Serve with fresh cilantro.