You can cook beef ribs at high temperature for a few minutes or cook them at a low temperature for a few hours, it depends on how tender you want them. Short ribs, as they're commonly known, have a high enough meat-to-bone ratio and marbling to cook with dry heat. But if you're looking for tenderness, low heat, around 300 degrees Fahrenheit, combined with three hours of cooking is the only way to go.
Prepping The Ribs
Trim any extraneous fat from the ribs and pat them dry with paper towels. Season the ribs to taste and sear them on all sides in an oiled frying pan until golden brown. Searing the ribs cooks off surface impurities and purges the protein-lipid byproduct meat releases in the first few minutes of cooking. If you don't sear the ribs, blanch them in boiling water for 3 full minutes, skimming the froth -- the protein-lipid byproduct -- off the surface, then cool them by holding them under cold running water.
Cooking the Ribs
Have the oven heated to 350 F by the time you finish searing or blanching the beef ribs. Place the ribs in a heavy braising dish or Dutch oven and add enough stock to nearly cover them. Cover the dish and lower the heat to 300 F. Cook the ribs until tender, about 2 to 3 hours, checking the stock and adding more as needed to keep them covered halfway throughout cooking.