Season the beef pieces with ½ tsp salt and freshly ground black pepper to taste.
Heat the olive oil in a large skillet over medium-high heat. Add the beef pieces and brown on all sides, about 3 minutes. Pour in the red wine and scrape the bottom of the skillet to pick up all the bits and pieces stuck to it. Cook for 1 minute and turn off the heat.
Place the onions, garlic, Dijon mustard, Worcestershire sauce, mushrooms, thyme, 1 tsp salt, black pepper to taste, and 1 ½ cups beef broth into the crockpot. Add the browned beef pieces with the wine, and cook for 8 hours on low, or for 4 hours on high.
Make a slurry with the cornstarch and the remaining ½ cup beef broth and pour it into the crockpot 15 minutes before the cooking time is over. It’s time to cook the egg noodles.
Turn off the crockpot and mix in the heavy cream and cooked egg noddles.