I love using liquids to cook things, for two reasons: first, it tenderizes tough foods, most notably lower-grade cuts of meat. Second, if you use the right liquid it can add a ton of flavor to what you are cooking.
One of my favorite such dishes is a good pot roast. A pot roast is usually beef, but sometimes pork, and is generally from a tougher part of the animal. This means it came from a group of muscles that are used a lot in walking or grazing, which means the upper joints and the neck area. By contrast, the middle of the back, the ribs and the inside section of the ribs known as the "tenderloin", hardly get used at all, so do not get developed to the point of toughness that the shoulder and hip area do.
However, these developed areas, although tougher, can be a lot more flavorful. We just need a way to tenderize the meat, and hot liquid is the perfect method.
So what constitutes the perfect liquid to use? First, it must be tasty itself, otherwise there is no point in using it. Second, it must be capable of dissolving flavor molecules since that is how the flavor is spread throughout the meat. Third, it must match the taste of the meat, otherwise the flavors will clash and that is just no fun at all.
For beef, there are two perfect liquids: beef stock and red wine. Beef stock works, because it is tasty, and it naturally will match the beef flavor itself, but the collagen in the beef stock will also dissolve flavor molecules. Red wine is also tasty (as long as you like wine, that is), and it pairs well with beef, and the alcohol is also a good flavor carrier. However, alcohol evaporates quickly in the heat, so this benefit is limited. Usually I go for beef stock, and add a little red wine for flavor.
So what else can you add to the pot roast? Anything that adds a good aromatic flavor is welcome: onions, carrots, bay leaves, celery, pepper corns, garlic cloves, parsnips, turnips, coriander seeds, chili flakes have all made their way into my pot roasts. With the hot liquid, the roast just soaks up those flavors while the meat is tenderizing.
Just make sure to keep the meat at a simmer, and not a boil, as it is actually possible to over cook even a tough cut if the temperature is too high. But if you keep it low, then the meat just gets better and better. If your roast has a bone, all the better: it will add flavor (that's where beef stock comes from!) and once the meat starts falling off the bone you will know it is ready!
And if you need something to use up the extra beef later on, try my Beef Barley Soup Recipe -- it's an easy, hearty meal that never fails to please!