Creating this incredible Slow Cooker Beef Stroganoff involves a few simple steps:

1. Prepare the Beef: Start by trimming excess fat from the beef chuck roast and cutting it into 1-inch pieces.

2. Sauté Aromatics: In a skillet over medium heat, add a bit of oil. Sauté the chopped onion and minced garlic until fragrant and translucent.

3. Brown the Beef: In the same skillet, add the beef pieces in batches and sear until they are browned on all sides. This step adds depth to the flavor.

4. Transfer to Slow Cooker: Once browned, transfer the beef and sautéed onions and garlic to the slow cooker.

5. Add Mushrooms and Broth: Pour in the sliced mushrooms, beef broth, Worcestershire sauce, Dijon mustard, salt, black pepper, and paprika. Stir well to combine.

6. Cover and Cook: Cover the slow cooker lid and set it to low for 6-8 hours or high for 3-4 hours until the beef is fork-tender.

7. Thicken the Sauce: About 30 minutes before serving, mix the sour cream and flour in a bowl until smooth. Stir it into the slow cooker and allow it to heat through; this will thicken the sauce.

8. Adjust Seasoning: Taste and adjust the seasoning if necessary. You can add more salt or pepper to suit your preference.

9. Prepare the Noodles: While the stroganoff finishes cooking, bring a pot of salted water to a boil and cook the egg noodles according to the package instructions. Drain and set aside.

10. Serve: Spoon the Slow Cooker Beef Stroganoff over the egg noodles and garnish with chopped fresh parsley if desired.

These straightforward steps will guide you in creating a stunning meal that your loved ones will rave about.