Season the beef cubes with salt and black pepper evenly.
Heat olive oil in a large skillet over medium-high heat. Add the beef cubes in batches and brown on all sides, about 3-4 minutes per batch. Transfer browned beef to the crock pot.
Add diced onion and minced garlic to the skillet and sauté for 2-3 minutes until softened. Transfer onions and garlic to the crock pot.
Pour beef broth and Worcestershire sauce into the crock pot. Add dried thyme, dried rosemary, and bay leaves. Stir to combine.
Cover and cook on low for 7 hours or until the beef is very tender.
About 30 minutes before serving, cook the egg noodles according to package instructions until al dente. Drain and toss with unsalted butter. Set aside and keep warm.
Remove bay leaves from the crock pot. In a small bowl, whisk together cornstarch and cold water until smooth. Stir the cornstarch mixture into the crock pot. Cover and cook on high for 15-20 minutes until the sauce thickens.
Taste and adjust seasoning with additional salt and pepper if needed.
Serve the tender beef and sauce over the buttered egg noodles. Garnish with chopped fresh parsley.