Step 1: Add the Beef to the Slow Cooker - Put the beef stew meat into your crockpot and spread it out as evenly as you can. You do not need to brown it first for this version, which is one of the reasons I reach for this recipe on busy days. Breaking up any pieces that are stuck together helps the seasoning and cooking liquid reach the meat more evenly. This is also a good moment to trim away any unusually large pieces of hard fat if you happen to spot them.
Step 2: Season the Beef and Add the Aromatics - Sprinkle the salt and black pepper over the beef, then add the chopped onion and minced garlic. Do not worry about arranging everything beautifully. Once the slow cooker heats up, the onion will soften and settle down around the beef while the garlic works its way into the cooking liquid. I like getting those ingredients right against the meat because the smell that develops after a few hours is exactly what I want filling the kitchen at dinnertime.
Step 3: Add the Au Jus Mix - Sprinkle the packet of au jus mix evenly over everything in the crockpot. This little packet brings a concentrated savory beef flavor that makes a short ingredient list taste like it has been simmering with a much longer list of seasonings. Try to scatter it rather than dumping it all in one pile so it dissolves more easily once you add the liquid.
Step 4: Pour in the Water and Beef Broth - Pour the water and beef broth into the crockpot. Give everything a gentle stir so the au jus seasoning begins dissolving and the onion and garlic are distributed throughout the liquid. The beef does not need to be completely hidden beneath the broth. As it cooks, it will release its own juices and everything will settle together into a savory cooking liquid that eventually becomes the gravy for your noodles.
Step 5: Slow Cook Until the Beef Is Tender - Cover the crockpot and cook the beef for 3 to 4 hours on high or 6 to 8 hours on low. If your schedule allows it, I tend to like the longer low setting because slow, steady cooking gives stew meat plenty of time to soften. Either way, you are looking for beef that is tender enough to cut easily with a fork. Different slow cookers run a little differently, so use the texture of the beef as your best guide near the end.
Step 6: Thicken the Gravy if You Like - If you open the lid near the end and decide you want a thicker gravy, make a simple cornstarch slurry. Stir a small amount of cornstarch into cold water until completely smooth, then stir that mixture into the crockpot during the final 30 minutes of cooking. Start with a modest amount because the gravy will continue to thicken as it heats. I usually prefer enough body that the sauce coats a noodle, but not so much that the whole dish feels heavy or pasty.
Step 7: Cook the Egg Noodles - Shortly before you are ready to eat, bring a large pot of water to a boil and cook the wide egg noodles according to the package directions. This is the only real last minute cooking the recipe asks from you. Drain the noodles once they are tender. I like to stop right when they are done rather than letting them become overly soft because they will spend a little more time sitting in that hot beef gravy.
Step 8: Stir Everything Together and Serve - Add the drained egg noodles directly to the crockpot and gently stir until they are coated in the gravy and mixed with the tender beef. Give the noodles a minute or two to settle into all those savory juices. Spoon generous portions into bowls and scatter chopped parsley over the top if you are using it. This is the point when somebody usually wanders into my kitchen asking if dinner is ready, even though the smell answered that question ten minutes ago.