In this recipe, I always sear the beef before it goes into the slow cooker. While it's not an absolutely essential step, doing this is going to take the flavour of your dish to the MAX! Plus searing the beef will keep it's juices inside while it cooks, giving you beautiful tender beef. If you're pushed for time, you can skip the searing step... but if you have a couple of extra minutes, it's going to make a HUGE difference to your meal.