If your oxtail did not come sliced, remove it from the package and rinse it well. Place on a large cutting board and slice crosswise into sections of about 2 inches each. Cut away the extra fat from the oxtail. There is a significant amount of fat that can be removed.
Using either Sea Salt (my preference) or Kosher Salt, use a sufficient amount to rub into the meat on all sides. Place this in a container and let it set at room temperature for about 2 hours, or if you have time and prefer place in the refrigerator overnight.
After the meat has set, remove and rinse well. This must be rinsed very well to get the salt off the meat (I made the mistake of not rinsing well enough the first time I made this, and the results were nearly inedible).
Over medium high heat, place oil into a large oven-proof pot which has a lid.
NOTE: You can use a slow cooker (crock pot) if desired, and cook this overnight with excellent results. When this just begins to smoke, quickly sauté the garlic until it has a small amount of browning to the pieces.
Add your oxtail slices, and brown on all sides. You are just going to sear the outer meat without cooking it at this time.
Add your beef broth, balsamic vinegar, and enough red wine to cover the top of the meat by approximately 1 inch. Add the Rosemary, Thyme, Oregano and Tarragon. Mix well.
Cover your pot and put into the oven to cook for the next 3 to 4 hours, or until the meat is tender enough to fall from the bone. Check your meat several times over the course of cooking to make certain there is enough liquid, add more wine when needed. If using a slow cooker, leave on low overnight.
When your meat is done, in either the oven or the slow cooker, add your sliced leeks by spreading over the top. Cook for another 30 minutes in the oven, or increase your slow cooker to high heat for the remaining time.
The sauce should form a thick caramelized sauce in the pot which can be served with the meal as gravy. The fat should be skimmed off this sauce before serving.
Many people do not like the bones in their Oxtails, so if you prefer you can remove these by pulling any meat from them.
*I use a Malena Garnacha for this recipe. The Torres Malena Garnacha makes a good one, as it is not expensive and is good enough to serve alongside the dish. Remember when you are cooking with wines, if you won’t drink it, then you don‘t want to eat it in your cooking either. Unless you just do not like to drink wine, the wine you use should always be one that you would drink yourself or serve to others. Taste matters!
Oxtails In Caramelized Gravy Recipe: https://whatscookingamerica.net/cynthiapineda/oxtails/oxtailscaramelizedgravy.htm