Before cooking corned beef, what are the two things that should always be kept close by? The answer is simple: a bottle of pale ale and a jar of dijon mustard.
A meal of corned beef and cabbage takes a long time to cook because the beef comes from brisket, which is a tough cut of meat. The connective tissue has to break down if the meat is to become tender. Some people like to braise the beef in water, using salt and various spices, while others add beer to tenderize the meat.

Beer Can Tenderize Beef With Great Success
People have long been using beer to tenderize their beef, cooking the meat over low heat for several hours to ensure it stays soft. Beer is a good source for tannins and acids that break down the meat and thus tenderize it. The same can be said for wine, citrus, and vinegar, so those can also be used. But when it comes to using beer, two bottles of pale ale are a good option – even better when combined with garlic, onion, and bay leaves.
This style of cooking focuses on tenderizing the meat and infusing flavor, which is why patience is a virtue for any cook. After all, preparing the dish can take around two to three hours. Some use cabbage and potato salad to complement the meat and complete the dish.

Potato-Cabbage Salad Is a Great Side-Dish for Corned Beef
The cabbage and potatoes should be prepared separately from the beef. Instead of boiling the potatoes and flavoring them later, this recipe does the flavoring all at once. It includes white vinegar, mustard seeds, salt, sugar, and water. When these are cooked well, they are transferred to a heatproof bowl where they cool completely to infuse the flavor of the liquid with which they were made. When the potatoes cool, the cabbage is stirred in, and the entire mixture is refrigerated for one hour, with the occasional stirring.
When the corned beef is ready, it should be sliced against the grain of the meat. This is done so to produce an even more tender result. When the meat is sliced with the grain, it becomes tougher and stringier when someone chews it. Finally, the mustard should be added to the mix. Dijon mustard is great because it provides texture and makes for a great dipping sauce.