Preheat the oven to 350°F. Heat the vegetable oil in a Dutch oven over medium heat. Add the short ribs and sear them on all sides until browned. Remove the ribs from the pan.
Add the onion, carrot, leak, garlic and tomatoes. Cook on medium heat until the onion has softened. Deglaze the pan with red wine and stir. Add the rosemary, thyme, oregano and beef stock and bring to a boil. Remove from heat.
Add the seared short ribs back to the Dutch oven. Then add enough water to make sure the ribs are completely covered. Cover the Dutch oven and bake for 3 hours. Check the ribs after one hour and again after two hours to make sure there is enough liquid, otherwise they can dry out. Remove from the oven, skim off the fat and discard, and strain the liquid into a small saucepan. Keep the ribs covered. Heat the braising liquid on high for about 10 minutes.
If you have leftover short ribs, be sure to keep any leftover braising liquid.