When braising beef, it is important to sear the outside of meat, either in a frying pan or in a very hot oven. Once brown all round, the secret is to cook on low heat for as long as it takes to get soft. At least 3 hours. I have a secret that makes any beef succulent and delicious. I make a sauce, for example onions, red pepper, mushrooms , sweat them in oil then add some flour for thickening, then add water and the cook. I then add the juices of the braised beef to the sauce.
Once the beef is cooked, I carve into thin slices, cover with the sauce and leave to cook slowly on the Shabbat platter or in a cooker on 150 c for a few hours. The meat is delicious and tender, a wonderful treat for a Shabbat lunch.