Season the beef chunks with salt and pepper and then dredge with flour. Heat olive oil in a large skillet over medium-high heat. Add the beef chunks and brown in batches on all sides. Remove to a plate.
Once the beef is cooked add it to the slow cooker. Add onions, garlic, beef broth, beef base, beer and mustard. Add thyme sprigs and bay leaves. Cover and cook on low for 8 hours.
About 20 minutes before serving cook the egg noodles according to package directions. Drain and set aside. Mix 2 tablespoons of flour with 3 tablespoons of beef broth. Stir into the beef in the slow cooker. Increase the heat to high and cook for 10-15 minutes.